Given: Number of days for which food provided = 30 days Number of people who left =
1
5
Calculation: Let the food consumed by 1 man in 1 day be x and total men be y Let the time after which people left be z days Then the total quantity of food = 30xy Food consumed by y men in z days = xyz Remaining food = 30xy - xyz = xy(30 - z) After z days, total men =
4y
5
Food consumed by
4y
5
men in 1 day =
4xy
5
Time taken for 4y/5 men to consume remaining food =