Answer:
20 days
Explanation:
40 students finish the food in 30 days. logically more students mean food is finished faster, so the number of days is inversely proportional to the number of students.
let d be the number of days and s be the number of students.
our relation will be d = k/s where k is the constant of proportionality.
so, we have 30 days and 40 students.
30 = k/40 and multiplying both sides by 40 we get k = 1200.
finally, for 60 students, we have d = 1200/60. the right hand side simplifies to 120/6 which again becomes 20.
thus, we have d = 20. so, it will last 20 days.