Answers Week 10

Quants 19 - Pipes and Cisterns
Two pipes can fill a cistern in 14 hours and 16 hours respectively. The pipes are opened simultaneously and it is found that due to leakage in the bottom it took 32 minutes more to fill the cistern. When the cistern is full, in what time will the leak empty it?

Work done by the two pipes in 1 hour = 1/14 + 1/16 = 15/112

Time taken by these pipes to fill the tank = 112/5 = 7 hours 28 hours

Due to leakage, time taken = 7 hours + 28 hours + 32 hours = 8 hours

Work done by two pipes + leak in 1 hour = 1/8

Work done by the leak in 1 hour = 15/112 - 1/8 = 1/112

Leak will empty the full cistern in 112 hours.


Logical 19 - Situation Reaction Test
While travelling in a train, you notice a man from the coach behind yours fall off the train. You would
a) pull the alarm chain so that the train may stop and the man may be helped
b) shout at the falling man asking him to get up quickly and entrain
c) jump off the train to assist the falling man
d) wait till the train stops at the next station and inform the railway authorities there

Clearly, the situation demands taking quick action to provide help to the victim which in turn necessitates that the train be stopped immediately. Hence, the answer is a.


Logical 20 - Ranking Test

If Atul finds that he is 12th from the right in a line of boys and 4th from the left, how many boys should be added to the line such that there are 28 boys in the line?

Number of boys in the line = 11 + 1 + 3 = 15

Number of boys to be added = 28 - 15 = 13.


Quants 20 - Stocks & Shares
The cost price of a Rs. 100 stock at 4 discount, when brokerage is 1/4% is:

Cost Price = Rs. (100 - 4 + 1/4) = Rs. 96.25