Question

A camp has food stock for 500 people for 70 days if 200 more people join the camp how long will the stock last in long method

Answer 1

500 people food stock last 70 days
700(200+500)people food stock last be x
so
500/70=700/x
(cross multiplying)
500x=70X700
500x=49000
x=49000/500
x=98
so it 98 days

Answer 2

if for 500 men the stock of food is for 70 days.

so let ,
200 more men join it means now total men=500+200=700 can finish it in x days.

now more people means the food stock lasts in less days so this is the case of inverse proportion.
now for 500 men food lasts in 70 days.
so for 1 man food lasts in 70×500.
and for 700 men food lasts in 70×500/700
=35
so the food lasts in 35 days...... ...