Question

100 students have provision for 30days after 20days 20 students are leaving in how many days remaining food will be lost​

Answer 1

Let us suppose that each student eats x kg of foodstock per day.

Then total stock consumes by 100 students for 1 days will be 100x kg

…..for 30 days it will be =30*100*x kg=total stock available in hostel.

……for 10 days food stock consumed will be=10*100*x kg.

So food stock left after 10 days will be 20*100*x kg.

Let us now suppose the food stock is going to last for D days for remaining 80 students as 20 students left hostel.

Then the following equation holds

80*x*D=20*100*x

Therefore D=2000/80=25 days

So food will last for 25 days after the 20 students left hostel

Answer 2

Let us suppose that each student eats x kg of foodstock per day.

Then total stock consumes by 100 students for 1 days will be 100x kg

…..for 30 days it will be =30*100*x kg=total stock available in hostel.

……for 10 days food stock consumed will be=10*100*x kg.

So food stock left after 10 days will be 20*100*x kg.

Let us now suppose the food stock is going to last for D days for remaining 80 students as 20 students left hostel.

Then the following equation holds

80*x*D=20*100*x

Therefore D=2000/80=25 days

So food will last for 25 days after the 20 students left hostel