A garrison of 750 men has provision for 20 weeks, if at the end of 4 weeks, they are reinforced by 450 men, how long the provision will last?
OA is 10 weeks
someone explain!
OA is 10 weeks
someone explain!
Let provision for 750 men for 20 weeks = x
Provision for 1 man for 1 week = x/(20*750)
Provision for 750 men for 1 week = x/20
Provision used up in first 4 weeks = 4* x/20 = x/5
Provision remaining = x - x/5 = 4x/5
Men added = 450. So, total men now = 750 + 450 = 1200
Provision for 1200 men for 1 week
= 1200 * x/(20*750) = 2x/25
Therefore no of weeks provision will last
= (4x/5)/(2x/25)
= 10 weeks
