Question

Four cousins were born at two-year intervals. The sum of their ages is 36. How old are they?

Answer 1

6, 8, 10, 12

Explanation:

x + (x + 2) + (x + 4) + (x + 6) = 4x + 12.

4x + 12 = 36

24 = 4x

x = 6

Answer 2

They are 6, 8, 10, 12 years old.

all of those added is 36 and two-year intervals translates to 2 years apart per cousin.