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
Zanzabum
3 years ago
9

One pipe can fill a tank in 36 minutes, a second can fill it in 9 minutes, and a third can fill it in 12 minutes. If the tank is

empty, how long will the three pipes, operating together, take to fill it?
Mathematics
1 answer:
Romashka-Z-Leto [24]3 years ago
6 0

Answer:

4 1/2 minutes

Step-by-step explanation:

This is a classic work problem.  These are solved by finding out how much of the work being done can get done in a single unit of time.  In our case minutes.

If pipe 1 takes 36 minutes to fill the tank, then it can get 1/36 of the job done in a single minute.

If pipe 2 takes 9 minutes to fill the tank, then it can get 1/9 of the job done in a single minute.

If pipe 3 takes 12 minutes to fill the tank, then it can get 1/12 of the job done in a single minute.

The sum of all of these together will take x minutes. Our equation then is this:

\frac{1}{36} +\frac{1}{9} +\frac{1}{12} =\frac{1}{x}

We need to find the LCD of those numbers and multiply through by that LCD to get rid of the fractions, cuz who likes fractions?!  The LCD is 36x; each denominator, including the x, goes into 36x evenly and that's the lowest number that each goes into evenly.  Multiplying through by the LCD:

(36x)\frac{1}{36}+(36x)\frac{1}{9}+(36x)\frac{1}{12}=(36x)\frac{1}{x}

Reducing gives us the equation:

x + 4x + 3x = 36 and

8x = 36 so

x = 4.5 minutes or 4 1/2 minutes

You might be interested in
Which 3 expressions have the same value?
valina [46]

Answer:

A. C. D.

Step-by-step explanation:

Original: 10-5(2)+(18-11)=7

A: 28/(4)=7

C: 49-43+(1)=7

D: 30-25+(2)=7

5 0
3 years ago
What is a common denominator for 1/7 and 1/3?<br><br> a 18<br> b 21<br> c 3<br> d 4
Nataliya [291]

Answer:

B. 21

Step-by-step explanation:

The fractions are there to just make the problem seem complicated, but just rewrite it without the fractions.

"What is a common multiple for 7 and 3?"

In this problem it's easy, all you have to do is guess and check.

A: A doesn't work. 7 is not a factor of 18.

B: B works! Both 3 and 7 are factors of 21.

C: C doesn't work. 7 is not a factor of 3.

D: D doesn't work. Neither are a factor of 4.

They only leave us with one solution, B.

6 0
2 years ago
The opposite corners of a quadrilateral are right angles. The quadrilateral is not a rhombus. What kind of quadrilateral is this
tatiyna
A rhombus is a 4 sided shape with equal lengths. Even though it has equal lengths, it has opposite sides that are parallel, and angles that are equal. It also has diaginols (dashed lines) meat in the middle
8 0
2 years ago
A bridge constructed over a bayou has a supporting arch in the shape of an inverted parabola. Find the equation of the parabolic
babymother [125]

Answer: f(x) = -0.016x² + 1.6x

Step-by-step explanation:

If the lenght of the road over the arch is 100m, we can consider a coordinate plane and say that the road starts at point (0,0) and finishes at (100,0). The vertice of the parabola is at point (50,40), because the maximum height is 40 and it is always in the middle point of the roots.

So, we have

(0,0) (50,40) (100,0)

A quadratic function is always on the form: f(x) = ax² + bx + c

0 = a0² + b0 + c

40 = a50² + b50 + c

0 = a100² + b100 + c

0 = a0² + b0 + c → c = 0 ∴

40 = a50² + b50

0 = a100² + b100

_________________________

2500a + 50b = 40 (*2)

10000a + 100b = 0

_________________________

5000a + 100b = 80

10000a + 100b = 0 (-)

__________________________

-5000a = 80

-a=80/5000

a=-0.016

∴

2500a + 50b = 40

2500.(-0.016) + 50b = 40

-40 + 50b = 40

50b = 80

b = 80/50

b = 1.6

This way f(x) = -0.016x² + 1.6x

6 0
3 years ago
0.135 written as a fraction is _____.<br><br><br><br> 5/37<br><br> 27/100<br><br> 27/200
sergij07 [2.7K]
First it would be 135/1000. Then you'd have to simplify.

Simplified, it would be 27/200.
4 0
3 years ago
Read 2 more answers
Other questions:
  • There are twice as many liters of water in one container as in another. If 8 liters of water are removed from each of the two co
    15·1 answer
  • Twice the sum of m and Five
    8·1 answer
  • Which equation represents the line that is perpendicular to y= 3/4x + 1 and passes through (-5, 11)
    14·1 answer
  • Evaluate 2x-7 when x=5
    5·2 answers
  • Type the integer that makes the following addition sentence true:<br> -6 ??? = -8
    10·1 answer
  • Jack left a tip of $5.75 for his waiter. If this represents 20% of his meal, what was the cost, in dollars, of Jack’s meal witho
    7·1 answer
  • (4) please try and find the area of a triangle thank you
    5·2 answers
  • 6 more than the square of r is same as 33 .
    8·1 answer
  • Complete the frequency table using 6 intervals beginning with 1-15.
    6·1 answer
  • Select two ratios that are equivalent to 4:18.
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!