The speed of a stream is 3 km per hour. A boat travels upstream 12 km and then returns to its original position downstream along the same route. If the speed of the boat in still water is 9 km per hour, what is the average speed of the boat for the entire round trip?

Answers

Answer 1

Answer:

7 km

Step-by-step explanation:

let the speed of boat in still water is x km/hr. 

given speed of stream is 3 km/hr. 

then speed of boat upstream = ( x - 3) km/hr

speed of boat downstream = (x + 3 ) km/hr 

Distance travelled upstream = 4 km

time taken to travel upstream = distance travelled upstream / speed of boat 

upstream

= 4 / (x - 3 ) .............(1) 

Distance travelled downstream = 10 km

time taken to travel downstream = distance travelled downstream / speed of boat 

downstream

= 10 / (x + 3) ............(2)

given that boat takes same time to travel upstream and downstream.i.e; (1) & (2) are equal

i.e. 4/(x-3) = 10/ (x + 3 ) 

4 * (x +3 ) = 10 * (x- 3)

4x + 12 = 10x - 30

12 + 30 = 10x -4x 

42 = 6x 

x = 42 / 6 = 7. 

i.e speed of boat in still water is 7 km/hr.


Related Questions

Please help! Thanks!​

Answers

Answer:

G.) 6

Step-by-step explanation:

The way the question is worded leads me to believe you're looking for the range. In this case, it is 6, because 12 (the greatest valued data point) minus 6 (the least valued data point) is 6.

Select three ratios that are equivalent to 8 : 5

Answers

Answer:

16:10, 24:15, 32:20, etc.

Step-by-step explanation:

anyone question 8 pleaseeeeeeeeeee

Answers

Answer:

$200 and $450

Step-by-step explanation:

We can start by assigning variables to our unknowns.

Our unknowns are the price for a DVD player and the price for a television.

x= price of a television

y= price of a DVD player

Next, let's translate the given information into a system of equations.

two televisions and three DVD players for $1750

2x+3y=1750

four televisions and one DVD player for $1250

4x+y=1250

Since the instructions did not specify, I will use substitution to solve, however you can also use elimination.

First, from the second equation, we subtract 4x from both sides.

4x+y-4x=1250-4x

y=1250-4x

Now we plug 1250-4x for y in the first equation.

2x+3y=1750

2x+3(1250-4x)=1750

Distribute.

2x+3*1250-3*4x=1750

Simplify.

2x+3750-12x=1750

Combine like terms.

-10x+3750=1750

Subtract 3750 from both sides

-10x+3750-3750=1750-3750

-10x=-2000

Divide both sides by -10

x=200

A television costs $200.

Now using that, we can plug that into one of the original equations. I'll use the second one.

4x+y=1250

4(200)+y=1250

800+y=1250

Subtract 800 from both sides.

y=450

A DVD player costs $450

You can plug those values back into the other equation (the first one) to double-check if you'd like as well.

URGENT LOTS OF POINTS

Answers

Answer:

+2

Step-by-step explanation:

Answer:

its +2

Step-by-step explanation:

PLZ THANK FIVE STARE AND GIVE BRAINLIEST.

What is 2+2? xd noob

Answers

Answer:

4

Step-by-step explanation:

You can count on your fingers if you need to or use a calculator.

Answer:

2+2 is 4

Step-by-step explanation:

Order these lengths in order from least to greatest.

0.65 m
0.6 m
0.52 m
0.55 m
0.545 m

Answers

Answer:0.52, 0.545, 0.55, 0.6, 0.65

Source:trust me bro

Answer:

O.52 m, 0.545 m, 0.55 m, 0.6 m, 0.65m. :)

Step-by-step explanation:

6x+4y=42 -3x+3y=-6 by elimination

Answers

Answer:

x=5, y=2

Step-by-step explanation:

To solve this system, we need to find x and y. First, let's find x. In the first equation (6x+4y=42), subtract 4y on both sides to isolate 6x. This will result in 6x=42-4y. Divide by 6 on both sides to isolate x and get x=7-[tex]\frac{2}{3}[/tex]y. Now we know what x equals. Go to the second equation ad plug this into it. So instead of -3x+3y=-6, you'll have -3(7-[tex]\frac{2}{3}[/tex]y)+3y=-6. Use the distributive property to get -21+2y+3y=-6. Add 2y and 3y to get -21+5y=-6. Add 21 to both sides to isolate 5y and get 5y=15. Divide by 5 on both sides to isolate y and get y=3. Now that we know that y=3, we can plug this back into the equation that was bolded above so that we can find x, so we'll have x=7-[tex]\frac{2}{3}[/tex](3) since y=3, and we'll get x=7-[tex]\frac{6}{3}[/tex], or x=7-2, or x=5.

x=5

y=2

Answer: (5, 3)

Step-by-step explanation:

Solve by Addition/Elimination

6x + 4y = 42 −3x + 3y = −6

Multiply each equation by the value that makes the coefficients of x opposite.

      6x + 4y = 42

      (2) ⋅ (−3x + 3y) = (2) (−6)

Simplify (2) ⋅ (−3x + 3y).

      6x + 4y = 42

      −6x + 6y = (2) (−6)

Multiply 2 by −6. 6x + 4y = 42

      −6x + 6y = −12

Add the two equations together to e liminate x from the system.

      6x + 4y = 42

    ±6x + 6y = −12

             1 0y= 30

Divide each term in 10y = 30 by 10.

      10y  =     30

      10          10

Cancel the common factor of 10.

     y = 30/10

  Divide 30 by 10.

      y = 3

Substitute the value found for y into one of the original equations, then solve for x.

Substitute the value found for y into one of the original equations to solve for x. 6x + 4 (3) = 42

 Multiply 4 by 3.

      6x + 12 = 42

Move all terms not containing x to the right side of the equation.

      6x = 30

Divide each term by 6 and simplify.

      x = 5

The solution to the independent system of equations can be represented as a point.

(5, 3)

The result can be shown in multiple forms.

Point Form:

(5, 3)

Equation Form:

x = 5, y = 3

Which expression is equivalent to -44
PLease asap 12 points please dont just take them

Answers

Answer:

|44|

Those are not Ones, those are the straight lines you can type using the Shift key and the key underneath the Backspace :)

Step-by-step explanation:

-44 is 44 places away from zero, and |44| is also 44 places away from zero. For those who are wondering, this symbol: | if is placed around a certain number, the positive or negative effect on that number is taken away, and the number is just thought as of that many spaces away from zero. EX: -9 => |9| is now not negative

Answer:

One equation is -22+-22

What is the value of x?

Answers

Answer:

5

Step-by-step explanation:

Use the Pythagorean Theorem

a²+b²=c² plug in the info you have

a²+12²=13² (c is always the side opposite from the right angle)

Solve for a

a²+144=169

   -144  -144

a²=25   take the square root of both sides

√a²=√25

a=5

WILL GIVE BRAINLIEST PLEASE HELP URGENT
Harris graphs the system of equations to determine its solution.

5x−y=55x+y=15

What is the correct solution?

Enter your answer by filling in the boxes. (__,__)

Answers

(1/2, -25/2). because 60x=30 , x=1/2,5x1-2-y=15, y=-25/2.

The intersection point of a system of equation is the solution of the system.

The solution to the system of equations is (2,5)

The equations are given as:

[tex]\mathbf{5x - y = 5}[/tex]

[tex]\mathbf{5x + y = 15}[/tex]

See attachment for the graphs of [tex]\mathbf{5x - y = 5}[/tex] and [tex]\mathbf{5x + y = 15}[/tex]

From the graph, the point of intersection is (2,5).

Hence, the solution to the system of equations is (2,5)

Read more about system of equations at:

https://brainly.com/question/12895249

whats the answerrr??..

Answers

Answer:

d is the answer of the question

CAN SOMEONE PLEASE HELP ME ON NUMBER 3

Answers

Answer:

36

Step-by-step explanation:

Is the following a function? Each player’s jersey number paired with their age.

Answers

Answer:

Yes it is a function if the jersey numbers are the same as their age and they are all different ages.

Step-by-step explanation:

(Timed) Solve the system of equations work shown

Answers

Answer:There are 2 ways to solve this system: by substitution or by graphing. I will solve this system using both.

Substitution Method

For x:

[tex]y = \frac{5}{4}x - 2\\y = -\frac{1}{4}x + 19\\\\\frac{5}{4}x - 2 = -\frac{1}{4}x + 19\\\\\frac{3}{2}x - 2 = 19\\\\\frac{3}{2}x = 21\\\\x = 14[/tex]

For y:

[tex]y = \frac{5}{4}(14) - 2\\\\y = 17.5 - 2\\\\y = 15.5[/tex]

Solution:

[tex](14, 15.5)[/tex]

Graphing Method

According to this graph, the solution will be [tex](14, 15.5)[/tex].

Item 20 You pay $4.35 for 0.75 pound of American cheese. You buy 2.5 pounds of Swiss cheese for $7.98 per pound. a. How much less does American cheese cost per pound than Swiss cheese? $ less per pound b. How much more do you spend on Swiss cheese than on American cheese? $

Answers

Answer:

a. $2.18

b. $15.60

Step-by-step explanation:

a. Price per pound of American cheese = $4.35 / 0.75 = $5.8

Price per pound of Swiss cheese = $7.98

Difference in price per pound = $7.98 - $5.8 = $2.18

b. Total amount spent on swiss cheese = $7.98 x 2.5 = $19.95

Amount spent more on Swiss cheese than on American cheese = $19,95 - $4.35 = $15.60

can a pentagon have interior angles that measure 120°, 105°, 65°, and 95°? explain.

Answers

Answer:

No

Step-by-step explanation:

because firstly, pentagon is five sided figure and secondly, the sum of interior angled of a pentagon is 540°

No, the given angles can not be the measure of the pentagon angles.

What is the pentagon?

A pentagon is a polygon having five sides connected to each other to form a closed figure. The sum of the angles of the pentagon is equal to 540 degrees.

Given angles are 120°, 105°, 65°, and 95°. Here as we know that the pentagon is a polygon having five sides. The number of angles formed by all the sides of the pentagon is also five.

Here we have only four angles that are 120°, 105°, 65°, and 95°. But to form a pentagon there must be five angles and the sum of the angles should be 540 degrees.

Therefore, the given angles can not be the measure of the pentagon angles.

To know more about the pentagon follow

https://brainly.com/question/224658

#SPJ2

. Line / is shown on the graph below. If
another line is drawn, perpendicular to
line I, what must be its slope?
y
A. -3
B. 3
C. 0
D. undefined

Answers

What’s the 1st line slope
If the line is perpendicular to the other it would have the same slope

Sorry I can’t tell you the direct answer without the graph or the other line slope

Hopes this is helpful

The slope of the perpendicular line is -3, which is option A.

What is a slope?

In mathematics, a line's slope, also known as its gradient, is a numerical representation of the line's steepness and direction.

If a line passes through two points (x₁ ,y₁) and (x₂, y₂) ,

then the equation of a line is

y - y₁ = (y₂- y₁) / (x₂ - x₁) x (x - x₁)

To find the slope;

m =  (y₂- y₁) / (x₂ - x₁)

The given equation of the line is I: y = (1/3)x.

To find the slope of a line perpendicular to I, we need to take the negative reciprocal of the slope of I.

The slope of I is 1/3, so the slope of a line perpendicular to I is:

-1 / (1/3) = -3

Therefore, the slope of the perpendicular line is -3, which is option A.

To learn more about the slope;

brainly.com/question/3605446

#SPJ2

The complete question:

If another line is drawn, perpendicular to line I = y= 1/3x, what must be its slope?

A. -3

B. 3

C. 0

D. undefined

WILL MARK BRAINLIST!!!!
A string of lights is 69 1/3 feet long. The lightbulbs are spaced 8 inches apart. The diagram shows the beginning of the string and the end of the string. What is the total number of lightbulbs on the string of lights?

Answers

I think it is 8 because 8 * 8 is 64 and 8 * 9 is 72 so it couldn’t be more than 8

Answer: 104

Step-by-step explanation:

I multiplied 69 1/3 by 12 to get how many inches it would. Then I divided that answer by 8 and got 103.999999999999. If you round it then you would get 104.

If a class of 30 students have to split the boys and girls in hafe and 10% are girls, how meany girls are in the class

Answers

Answer:

10 girls

Step-by-step explanation:

Question 19
Ellie earns $10.50 per hour as a server working x hours per week. She also earns $8.50 per hour editing poetry for y hours per
week. Ellie needs to make at least $125 to pay her cell phone bill, but she has at most 17 total hours to work per week with
her busy college schedule.
The system of linear inequalities modeling this situation is shown.
10.50x +8.50 y 2 125
x + y 517
Which statement represents a solution to the system of linear inequalities?

Answers

Answer:

what are the statements

Step-by-step explanation:

The expression x + 0.25x can be used to determine a 25% increase in the number of blog views from last month to this month. What expression shows this another way?

Answers

Answer:

1.25x

Step-by-step explanation:

Given that :

25% Increase in number of blog views can be expressed as (x + 0.25x)

Another way to make this representation is :

Total number of blog views + 25% of total

Total should add up to 100%

Let number of views = x

Hence,

(100% + 25%) of x

125% of x

125%x

= 1.25x

Quadrilateral JKLM is a kite as such KM is a perpendicular bisector of J L at point P given that KP =4" JL equals 12" and AML equals 20" was the length of the permenter of the quad JKlM?

Answers

Answer:

40 + 4√13

Step-by-step explanation:

A kite is a quadrilateral (has four sides) with two pairs of equal adjacent sides. The longer diagonal of a kite bisects the shorter diagonal.

Since in kite JKLM, diagonal KM bisects JL, hence KM is the longer diagonal.

JP = LP

JL = 12

JL = JP + LP

12 = JP + LP

2JP = 12 (LP = JP)

JP = 6

We can find JK using Pythagoras theorem, hence:

JK² = JP² + KP²

JK² = 4² + 6²

JK² = 16 + 36

JK² = 52

JK = √52 = 2√13

JK = KL = 2√13

ML = JM = 20

Perimeter of kite = JK + KL + ML + JM = 20 + 20 + 2√13 + 2√13

Perimeter of kite = 40 + 4√13

HELPPPPPPPPP MEEEEE STARVINGGGGG

Actually help me with the screenshot though LOL

Answers

Answer: i think A, but might not be sry

Step-by-step explanation:

I am selling raffle tickets. It cost $155 to print the tickets and I want to make at least a $2,500 profit how much money do I need to raise to cover the cost of the printing and meet my goal

Answers

Answer:

Step-by-step explanation:

You need $2500 plus the amount to print the tickets. So 2500+155= $2655.

$155 will break even and then the $2500 will be the profit.

On god I will mark you as brainliest

Answers

SAS = equal triangle
x - 4 = 19
Solve the equation
Solution: x = 23

The graph of is shown on the grid.







Which ordered pair is in the solution set of ?

Answers

Answer:

where's the graph rn ?

Step-by-step explanation:

is this question complete?

Be a bit more specific

What’s the domain and range of a horizontal line?

What’s the domain and range of a vertical line?

Answers

Horizontal line would be y=1 (1 would change with whatever point the line goes through), vertical would be all real numbers which looks like a fancy R.

The horizontal line has infinite domains but a range that has only one value.

The vertical line has a domain is the -intercept, and its range is "all real numbers."

Given that,

The horizontal and vertical lines.

Since we know that,

Linear functions always have infinite domains and ranges.

The exception is when the graph is a horizontal line.

This happens for functions that equal a constant such as f(x) = a. These functions have infinite domains but a range that has only one value, a.

And, A vertical line that is the -axis has an infinite number of -intercepts. A vertical line is not a function;

Hence its domain is the -intercept, and its range is "all real numbers."

To learn more about the function visit:

https://brainly.com/question/11624077

#SPJ6

find slope of the line passes through (7, 3)and (9, 6​

Answers

Answer:

slope = 3/2

Step-by-step explanation:

(y2-y1)/(x2-x1)

= (6-3)/(9-7)

= 3/2

Hope this helps!       :3

plz mark as brainliest!

Solve problem in photo 8th math

Answers

square root of 20 = 4,472135954999579

To the nearest tenth: 4,5

There are 12 books on a shelf. 7of these books are new.
(a) What is the ratio of new books to used books?
(b) What is the ratio of all books to used books?

Answers

Answer:

(a) 7 : 5

(b) 19 : 5

Hope this helps :)

Answer:

(a) 5:7 ( 5 new to 7 used). (B) 12:7   (12 books to 7 used ones). You are welcome :)

Step-by-step explanation:

Other Questions
1 is 25% of what number Timbre describes:the type of wood used on string instrumentsthe time and breath required to play an instrumentthe piece of wood used on many woodwind instrumentsthe unique sound of a voice or instrument please do this Write a conjecture that describes the pattern below.3, 9, 27, 81... Write a summary of "At the Crossroads." A summary is a concise, complete, and accurate overview of a text PLEASE HELP !! Which words best describe the author's feelings about the day?1. happy and exhilarated2. battered and exhausted3. angry and frustrated4. easy and successful It rains 24 out of 30 days in a month.At the same rate, about how manydays would you expect it torain in 180 days? change the statement given below into a question beginning with: "will..." "we will meet again." A 6 pack of batteries cost $7.80. How much is 1 battery? Tu dtestes la chimie. What is the value of the expression 20/4 - (1/2 + 3 3/4) How does the politics of personal responsibility reinforce racism in the United States? Javed downloaded from the Internet two files that had a combined size of 696 megabytes. The size of the first file was290 megabytes, and it took 5 minutes to download, Assuming that the files downloaded at a constant speed, how longdid it take for the second file to download?2 minutes4 minutes7 minutes12 minutes Write an LC-3 assembly language program to read in a two-digit decimal number whose digits add up to less than 10 and display the sum of those digits in the next line.Sample execution (user input underlined) : Please enter a two-digit decimal number > 27. The sum of the digits = 9 1.) What should the title of this graph be? 1.)What are the 2 variables being studied by this graph? 1.)What is the relationship between these 2 variables? in Macbeth act 2, how is the murder of the king discovered? A farmer has 12 acres of land. He plans to plant w acres of wheat and b acres of barley on his land. If he plans to plant wheat in no more than 3 acres of land, which system of inequalities represents the possible values for b and w ? Look at the text feature. A man wearing layers of fur while standing in ice. How does this text feature support the information in "Roald Amundsen"? It shows how deep each layer of ice and snow is in the polar region. It shows the type of clothing that explorers wore for the cold climate. It shows the direction that the explorer and his crew traveled in. It shows the materials that were used to make tents at base camp. How can you create a blog that argues your viewpoint on a topic? I'll give brainliest to the first correct answer. Why did Phaeton ask his father to allow him to drive the sun across the sky?He wanted to distinguish himself above the other children of gods.He had made a wager with Epaphus that he could drive the sun.He wanted to show Epaphus he was, indeed, the son of Phoebus.He had entered into a chariot race with Epaphus. A truck travels from a factory to a gas station in 2 minutes. It stops at the gas station for 5 minutes. The truck then returns to the factory in 3 minutes, which graph best repdistance, y, in miles, of the truck from the factory after a certain amount of time, x, in minutes? (5 points)FactoryTrucksDieSAVE & EXITSUBMIT ALL ANSWERS08:27