GIKI Management Sciences MCQs

The leak rate is 1/9 - 1/12 = 1/36 tank per hour.
Thus, the leak alone empties the tank in 36 hours.

Speed equals distance divided by time.
Thus, 180 ÷ 3 = 60 km/h.

The pipe fills 1/6 of the tank per hour.
In 2 hours it fills 2/6 = 1/3.

Distance equals speed multiplied by time.
Thus, 72 × 2.5 = 180 km.

Their combined rate is 1/8 + 1/12 = 5/24 tank per hour.
Time is 24/5 = 4.8 hours.

To convert km/h to m/s, multiply by 5/18.
Thus, 54 × 5/18 = 15 m/s.

The net rate is 1/10 - 1/15 = 1/30 tank per hour.
Therefore, the tank fills in 30 hours.

To convert m/s to km/h, multiply by 18/5.
Thus, 20 × 18/5 = 72 km/h.

The net hourly rate is 1/4 - 1/12.
This equals 2/12 = 1/6.

Time equals distance divided by speed.
Thus, 12 ÷ 4 = 3 hours.

Their combined daily rate is 1/10 + 1/15 = 1/6.
Therefore, they complete the job in 6 days.

B's rate is 1/8 - 1/12 = 1/24.
Therefore, B alone needs 24 days.