1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Leto [7]
3 years ago
11

If it takes you 40 minutes to go 20 miles downstream and then 60 minutes on the way back, what is the speed of the current?

Mathematics
1 answer:
IrinaK [193]3 years ago
3 0

Answer:

Speed of Current = 5 miles per hour

Step-by-step explanation:

We know distance formula,

D = RT

Where

D is distance

R is rate

T is time

If we let speed of boat (assume) to be "x" and speed of current to be "c"

Then downstream rate is (with current) = x + c

Upstream rate is (against current) = x - c

40 mins to go 20 miles downstream, that means:

D = RT

20 = (x + c)(40)

and

60 minutes to go upstream, 20 miles, that means:

D = RT

20 = (x - c)(60)

Simplifying first equation:

40x + 40c = 20

Simplifying second equation:

60x - 60c = 20

Multiplying first equation by 60, we get:

60 * [40x + 40c = 20] = 2400x + 2400c = 1200

Multiplying second equation by 40, we get:

40 * [60x - 60c = 20] = 2400x - 2400c = 800

Now we add up both these equations:

2400x + 2400c = 1200

2400x - 2400c = 800

----------------------------------

4800x = 2000

x = 2000/4800 = 5/12

We need speed of current, that is "c", so we plug in the value of x into first equation and solve for c:

40x + 40c = 20\\40(\frac{5}{12}) + 40c = 20\\\frac{50}{3}+40c=20\\40c=20-\frac{50}{3}\\40c=\frac{10}{3}\\c=\frac{1}{12}

Speed of Current = 1/12 miles per minute

Since there is 60 minutes in an hours, that would be:

(1/12) * 60 = 5 miles per hour

Speed of Current = 5 miles per hour

You might be interested in
A farmers field has the dimensions 2 and 3/4 by 1 and 1/3. He needs to find the area of the field
Afina-wow [57]

Answer:

3 2/3 units²

Step-by-step explanation:

Since the field is rectangular in nature;

Area of the field = Length * Width

Given

Length = 2 3/4

Width = 1 1/3

Area of the field = 2 3/4 * 1 1/3

Area of the field = 11/4 * 4/3

Area of the field = 4/4 * 11/3

Area of the field = 1 * 11/3

Area of the field = 11/3

Area of the field = 3 2/3

Hence the area of the field is 3 2/3 units²

5 0
3 years ago
Which of the following represents the area of a rectangle with a length of (3x + 2)
Misha Larkins [42]

Answer:

WANNA HEAR SOME METAL

Step-by-step explanation:

WANNA HEAR ME ROAAAAAAAAAAAAAAAAAR

6 0
2 years ago
!!!!!!!!! PLEASE HELP !!!!!!!!!!<br><br><br> Solve x² - 6x - 7 = 0
sesenic [268]

Answer:

x = 7, -1

Step-by-step explanation:

4 0
2 years ago
How do i solve this question 58−(14)2
Naily [24]

Answer:

PEMDAS RULE

Step-by-step explanation:

STEP one is multiplication 58-14x2=58-28

STEP two is subtraction 58-28=30

Parenthesis

Exponent

Multiplication

Division

Addition

Subtract

3 0
3 years ago
Read 2 more answers
Take some time to fill in your notes, the area that is not shown in this video. Fill in the table with the values you think are
joja [24]

The x-values are the heartbeat(s) and the y-values are the time(s)

<h3>How to determine the x and y values?</h3>

The variables are given as:

Time(s) and Heartbeat(s)

As a general rule, the action that is being done is the independent variable.

The action here is the heartbeat.

So, the x-values are the heartbeat(s) and the y-values are the time(s)

A possible value of this is;

x = 100, y = 60 seconds

So, the ordered pair is (100,60)

When represented as ratio, we have;

Ratio = 60/100

Simplify

Ratio = 0.6 heartbeat per second

Read more about ordered pairs at:

brainly.com/question/8406931

#SPJ1

8 0
1 year ago
Other questions:
  • Wacky water park<br> Worksheet
    11·2 answers
  • In a randomly generated list of numbers from 0 to 6, what is the chance that each number will occur?
    6·2 answers
  • Sonya got 8 out of 10 questions right on a quiz. She got the same score on a quiz that had 20 questions. How many questions did
    8·1 answer
  • 7th grade math guys!! <br>Proportion equation?? <br>anyone help please???!!
    15·2 answers
  • Joe has some money in his
    13·2 answers
  • Four balls of wool will make 8 knitted Caps.How many balls of wool will Malcolm need if he wants to make 6 cups?
    12·1 answer
  • Sharon is 18 and would like to buy a house when she is 34. What is the discount factor for today's prices if the housing values
    5·2 answers
  • 8/10
    9·1 answer
  • What is If x represents the unknown part, which of the following shows a valid set of steps that can be used to find 15% of 30?
    12·1 answer
  • Examine Carmen's plans for rail lines at a train station.
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!