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
sveta [45]
3 years ago
11

An inlet pipe can fill a water tank in 12 hours. An outlet pipe can drain

Mathematics
1 answer:
Ira Lisetskai [31]3 years ago
6 0
<h3>Answer:   30 hours</h3>

============================================================

Explanation:

Let's consider the tank's full capacity is 240 gallons. I'm picking this number because 12*20 = 240.

If the tank is 240 gallons, then the inlet pipe can fill it at a rate of 240/12 = 20 gallons per hour. Note after 12 hours, we have 12*20 = 240 gallons filled assuming the outlet pipe is sealed shut.

At the same time, the outlet pipe is draining at a rate of 240/20 = 12 gallons per hour. After 20 hours, the outlet pipe would drain out 12*20 = 240 gallons assuming the inlet pipe is not adding any water.

With the two pipes playing this tug-of-war battle, the inlet pipe ultimately wins because it's adding more gallons of water each hour, compared to the amount drained per hour. The net change is +20-12 = 8 gallons per hour.

This means it will take 240/8 = 30 hours to fill the tank with both pipes open.

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

Another approach:

The inlet pipe can fill the tank in 12 hours, so it gets 1/12 of the job done per hour. The outlet pipe drains the tank in 20 hours, so it gets 1/20 of the job done in one hour.

The net change is 1/12 - 1/20 = 5/60 - 3/60 = 2/60 = 1/30

This means that when both pipes are open, 1/30 of the job is done per hour. By "job", I mean "filling the tank".

If x is the number of hours needed to do one full job, then we can multiply that by the unit rate (1/30) and set the result equal to 1

(rate)*(time) = 1 job

(1/30)*x = 1

x = 30*1

x = 30

It takes 30 hours to do the job with both pipes open.

You might be interested in
Grace read 4 days this week. She read 10 minutes each day. If her teacher wants her to read it a total of 60 minutes, how many m
Slav-nsk [51]

She needs to read 20 more minutes.

10x4=40

60-40=20

4 0
2 years ago
PLEASE HELP!!!!!! the sum of a number times 10 and 15 is at most -17
Brilliant_brown [7]

Let the number = x

Writing the equation you have:

10x + 15 <= -17

Solve for x

Subtract 15 from both sides:

10x <= -32

Divide both sides by 10:

X <= -32/10

Simplify:

X <= -16/5 as a fraction or -3.2 as a decimal

3 0
3 years ago
Which of the following equations is the equation 2 - 3y + 6x = 0 written in slope-intercept form?
IgorLugansk [536]
The answer us c
..........
7 0
3 years ago
Read 2 more answers
(r + 14x + 55x + 48) \(x + 6)
balu736 [363]

Answer:

r + 69x + 48 / x + 6

Step-by-step explanation:

3 0
2 years ago
Jane babysits for $8 per hour. She earned $240 last week. This equation represents the number of hours, h, Jane babysat last wee
Tatiana [17]

Answer:

30 Hours

Step-by-step explanation:

8h=240

240÷8=30

8 0
3 years ago
Other questions:
  • Somebody Help In This Homework!
    15·1 answer
  • Mariah spent $9.50 on 9 pounds of limes and pears. Limes cost $0.50 per pound and pears cost $1.50 per pound. Let l be the numbe
    11·1 answer
  • What is the major difference between Fourier Transform and Z-Transform??.
    10·1 answer
  • Ava was making muffins. She used 1 1/3 tsp of cinnamon and 1/2 tsp of nutmeg. How many teaspoons of spice did Ava use?  
    9·1 answer
  • Order the number from least to greatest<br> -1.4,-3/5,9/2,0.9
    13·1 answer
  • PLZ HELP only got 30 minutes left will brainliest. What is the rate of change of the function? –2 --1/2 1/2 2
    7·2 answers
  • Help i’ll give brainliest
    10·2 answers
  • The measures of the angles of a triangle are shown in the figure below. Solve for x.
    12·1 answer
  • Please help 28 POINTS
    14·2 answers
  • 17. Which of the following transformations does NOT preserve congruence?
    12·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!