The correct option is D 22.5 days
Given, 225 students have provisions for 40 days.
After 15 days,
Provisions for 225 students will last for (40 - 15) = 25 days.
and, the number of students = 225 + 25 = 250.
We know that, if the number of students increases, then, the number of days for which the provision lasts will decrease.
So, Number of students(x) ∝1Number of days(y)
∴ x1x2 = y2y1
Given,
x1 = 225 students
y1 = 25 days
x2 = 250 students
and y2 = number of days
⇒225250=y225
⇒ 225 × 25 = 250 × y2
⇒ y2 = 225 × 25250 = 22.5 days
So, the provision will last for 22.5 days.