40/3 days, (13.33 days)
Step-by-step explanation:
Set up the equation, 15/20 = 10/x, and then use cross mutiply to solve it.
10 * 20 = 15x, x = 200/15 = 40/3
Why?
b/c if each pig eats the same amount of food, then the ratio between the number of pigs and days should remain constant.
