Question

There are 20 bears in a zoo. What will be their population after 3 years, if the population doubles each year?

Answer 1

120

Explanation:

20+40+60 = 120

If we double it, we have to keep adding 20 each year and stop at 3 so the answer is 120

Answer 2

160

Explanation:

20 x 2 = 40

40 x 2 = 80

80 x 2 = 160

It stops at 3 years.