A hostel has provision for 800 men tor 24
days at rate of 2 kg per man per day. For how many men is the provisions
sufficient, for 20 days at the rate of 1 x 5 kg per man per day? .
food available = (800 x 24 x 2) kg
Let the number of men be x
So 800 x 24 x 2 = x x 20 x 1 x 5
x = = 1280
The food is sufficient for 1280 men. .
Two pipes can fill a tank in 15 minutes and
25 minutes respectively. Both pipes are opened together and after some time the
first pipe is closed and the tank is filled in a total of 15 minutes. For how
many minutes is the first pipe open? .
Second pipe is opened for 15 minutes. So,
part of tank filled by the second pipe =
So is filled by first pipe. First pipe can fill of tank in x 15 = 6 minutes. So the first pipe is opened for 6 minutes.
Pipe A can fill a tank in 8 hours and pipe B
can empty the full tank in 15 hours. If the both pipes are opened together, in
how much time will the tank become full? .
tank filled by pipe A in 1 hour r =
Part of the tank that can be emptied by B in
1 hour = . When both pipes are opened the part of the tank filled in 1 hour
So the tank will become full in = hours.
12 men can do a work in 15 days working 8
hours a day. In how many days can 9 men do the same work, working 10 hours a
We have M1D1H1
So 12 x 15 x 8 = 9 x D2 X 10
D2 = 16 days. .
Due to a leak at the bottom, pipe Y takes 15
hrs to fill the tank and the leak alone can empty the full tank in 10 hrs. In
what time can pipe Y alone fill the tank when the leak is closed? .
Y takes x hrs to fill the tank when the leak is closed. .
Due to the leak Y takes 15 hrs to fill the
Leak alone can empty the fill tank in 10 hrs.
&⇒ x = 6 hrs.