Pipe A, working alone, can fill a tank in 12 hours. Pipes A and B, wor

Question

Pipe A, working alone, can fill a tank in 12 hours. Pipes A and B, working together, can fill the tank in 8 hours. In how many hours, working alone, can pipe B fill the tank ?

A. 8 hrs
B. 12 hrs
C. 16 hrs
D. 20 hrs
E. 24 hrs

yashikaaggarwal · Answer

Answer is 24 hours.
Let the total capacity is 12litre.
A fill 1litre/hour
12litre /12 hour.
A + B filled it in 8 hours 
That means A could only fill 8 litres. Rest 4(12-8) litres is filled by B in 8 hours 
That means B fill 0.5 litre per hour. 
It wil take 12/0.5 hours = 24 hours for B to fill the tank own it's own.
OA is E

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Archit3110 · Answer

rate of A = 1/12
rate of B = x
together rate of A & B = 
x+12/12x = 1/8
solve for x = 24 hrs
OPTION E

Saiharish98 · Answer

Rate of B alone = 1/((1/8)-(1/12)) 
 =24 hrs

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Ravixxx · Answer

SOLUTION

We can set-up the equation:

\frac{1}{A} +\frac{1}{x} = 8

\frac{1}{A} = \frac{1}{12}

\frac{1}{12}+ \frac{1}{x} = 8

2x+24=3x 
 x=24

ANSWER E

ScottTargetTestPrep · Answer

The rate of pipe A is 1/12, and the rate of both pipes is 1/8. Letting B = the number of hours it takes pipe B to fill the tank working alone, we see that pipe B’s rate is 1/B. Thus, we can create the equation:

1/12 + 1/B = 1/8

Multiplying by 24B, we have:

2B + 24 = 3B

24 = B

Answer: E

TheNightKing · Answer

Let work be 96 units.

A can do 96 units in 12 hours. That's 8 units per hour.

A+B can do 96 units in 8 hours. That's 12 units per hour.

That means B alone is doing 4 units per hour but we need to find out the time.

Time taken by B alone = 96/4=24 hours

Answer E

Neha2404 · Answer

IMO-E

Pipe Efficiency Time. Total work
A. 4 12. 48
A+B. 6 8. 48

Total work is equal to LCM OF 12 & 8
Efficiency of B=. 6-4 
 =2
Time taken by B. =Total work/efficiency 
 =48/2
 =24 hour

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satya2029 · Answer

Ra=1/12
Ra+Rb=1/8
Rb=1/8-1/12
Rb=1/24
E:

bumpbot · Answer

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Pipe A, working alone, can fill a tank in 12 hours. Pipes A and B, wor

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