Jack's age is 3 times more than his younger cousin, Gabby's age and 4 times more than his younger brother's. If Jack's younger cousin's age is 8, how old is his younger brother?

1 answer

j = 3g
j = 4b
g = 8

Now just find b:

j = 3*8 = 24
24 = 4b
b = 6