# Aptitude Pipes and Cisterns Test Paper 2

6) A cistern can be filled by an inlet in 6 hours and can be emptied by an outlet in 8 hours. If the inlet and outlet are opened together, in what time the cistern can be filled?

1. 24 hours
2. 26 hours
3. 20 hours
4. 18 hours

Correct Option (A)

Part of the tank filled by the inlet in one hour =
Part of the tank emptied by the outlet in one hour =
Net part of the tank filled in one hour = -

part of the tank is filled in one hour

∴ The whole tank will be filled in 24 hours.

Solution 2:
Apply formula; =

X = 6 hours

Y = 8 hours
∴ Required time = = 24 hours

7) 20 buckets can fill a tank when the capacity of each bucket is 12 liters. If the capacity of each bucket is 10 liters, find the number of buckets required to fill the tank.

1. 30 buckets
2. 34 buckets
3. 24 buckets
4. 27 buckets

Capacity of each bucket = 12 liters

20 buckets can fill the tank. So, capacity of tank = 20 * 12= 240 liters

New capacity of bucket = 10 liters

So, 10 liters can be poured into the tank by one bucket

8) Two pipes working together can fill a fish tank in 12 minutes. If one pipe fills the fish tank 10 minutes faster than the second pipe, in what time the second pipe alone can fill the fish tank?

1. 20 minutes
2. 25 minutes
3. 30 minutes
4. 35 minutes

Let the first pipe fill the reservoir in X minutes

So, the second pipe will fill the reservoir in (X+10) minutes

As per question;

12X +120 + 12X = X2 + 10X

X2 +10X 24X -120 = 0

X2 14X -120 =0

X2 - 20X+6X 120=0

X(X-20) +6(X-20) =0

(X+6) (X-20) = 0

X = 20

∴Second pipe will fill the reservoir in 20 + 10= 30 minutes

9) 25 outlets working 6 hours a day, can empty a reservoir in 10 days. If only 15 outlets are operational and work for 4 hours a day, in how many days the reservoir can be emptied?

1. 20 days
2. 18 days
3. 22 days
4. 25 days

Apply formula used in work and time problems; M1D1T1W2 = M2D2T2W1

M1= 25 outlets, D1=10 days, T1= 6 hours/day, W2 = to fill the reservoir

M2= 15 outlets, D2=? T2 = 4 hours/day, W1= to fill the reservoir

W1=W2

So we have; M1D1T1= M2D2T2

25*10*6=15*D2*4

1500 = 60 * D2

10) Pipe A can fill a tank in 12 minutes whereas pipe A along with pipe B can fill the same tank in 8 minutes. In what time pipe B alone can fill the tank?

1. 24 minutes
2. 20 minutes
3. 25 minutes
4. 22 minutes

Part of the tank filled by pipe A in one minute=

Part of the tank filled by A+B in one minute =

Part of the tank filled by B alone =

∴ Pipe B will fill the whole tank in 24 minutes.

Solution 2:

X= 12 minutes

Y=?

As per question;

12Y= 8Y+96

4Y= 96

Y = 24 minutes

Aptitude Pipes and Cisterns Test Paper 1
Aptitude Pipes and Cisterns Test Paper 3
Pipes and Cisterns Concepts