Question

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Six small pumps and three large pumps are fitted to a tank. Each small pumps works 2/3rd the
rate of each large pump. If all the pumps work together, what fraction of the time taken by a single
large pump, will they take to fill the tank?
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Answer 1

Given: Six small pumps and three large pumps are fitted to a tank. Each small pumps works 2/3rd the  rate of each large pump.

To find: What fraction of the time taken by a single  large pump, will they take to fill the tank?

Solution:

• Now we have given that there are six small pumps and three large pumps.

• According to question, each small pumps works 2/3rd the  rate of each large pump.

• So, let the large pump fill the tank by rate 3L / hr .

• Eventually, the rate of small pump will be 2L / hr.

• Now in 1 hour, the tank filled will be:

• By larger pumps: 3 x 3 = 9 L

• By smaller pumps: 2 x 6 =  12 L

• So total water will be: 9 + 12 = 21 Litres of water in one hour.

• So one pump will take: 3/21 = 1/7 hour.

Answer:

              So 1/7 hour will be taken by one large pipe to fill the tank.