variation

38(a) We have NP = K. Sub. N = 30 and P = 100 => K = 3000

Let P = 120, N = 3000/120 = 25

The food bank can supply 120 people in need for 25 days.

(b) Yes. Let say people increase to 1.5P

Then N' = K/1.5P = N/1.5 = 2N/3

So, if we can provide 3/2 times of food (shortens 50% of the food supply period), then the no of days supplied does not changed.