# Pipes and Cisterns Quiz Set 018

### Question 1

One tap can fill a tank 4 times faster than the other. If they together fill it in 7 minutes, how much time does the slower alone take to fill the tank?

A

35 mins.

B

5 mins.

C

3 mins.

D

7 mins.

Soln.
Ans: a

Let the one minute work of the taps be 1/x and 4/x. We have \$1/x + 4/x = 1/7\$, which gives x = 5 × 7 = 35 mins.

### Question 2

Pipe A can fill a cistern in 105 minutes, while the pipe B can fill it in 70 minutes. They are alternately open for 1 minute. How long will it take the cistern to fill completely?

A

84 mins.

B

85 mins.

C

83 mins.

D

86 mins.

Soln.
Ans: a

Let the total time taken be 2x minutes. Both X and Y run for x mins. So \$(x/70 + x/105)\$ = 1. Solving for x, we get x = 42, which gives 2x = 84.

### Question 3

One tap can fill a tank 4 times faster than the other. If they together fill it in 6 minutes, how much time does the slower alone take to fill the tank?

A

30 mins.

B

5 mins.

C

3 mins.

D

7 mins.

Soln.
Ans: a

Let the one minute work of the taps be 1/x and 4/x. We have \$1/x + 4/x = 1/6\$, which gives x = 5 × 6 = 30 mins.

### Question 4

Two pipes, A and B, can fill a cistern in 8 and 16 mins respectively. There is a leakage tap that can drain 16 liters of water per minute. If all three of them work together, the tank is filled in 15 minutes. What is the volume of the tank?

A

\$132{12/29}\$ liters.

B

\$138{5/28}\$ liters.

C

\$122{29/31}\$ liters.

D

\$126{21/31}\$ liters.

Soln.
Ans: a

Work done by the leakage in 1 min is \$1/8 + 1/16 - 1/15\$ = \${29/240}\$. This work is equivalent to a volume of 16 liters. So, the total volume is 16 × \${240/29}\$ = \${3840/29}\$, which is same as: \$132{12/29}\$ liters.

### Question 5

Two pipes, A and B, can fill a cistern in 14 and 16 mins respectively. There is a leakage tap that can drain 7 liters of water per minute. If all three of them work together, the tank is filled in 18 minutes. What is the volume of the tank?

A

\$89{25/79}\$ liters.

B

\$91{37/78}\$ liters.

C

\$86{11/81}\$ liters.

D

\$90{1/27}\$ liters.

Soln.
Ans: a

Work done by the leakage in 1 min is \$1/14 + 1/16 - 1/18\$ = \${79/1008}\$. This work is equivalent to a volume of 7 liters. So, the total volume is 7 × \${1008/79}\$ = \${7056/79}\$, which is same as: \$89{25/79}\$ liters.

Updated on 2017-05-17.

Posted by Parveen(Hoven),
Aptitude Trainer