Question 1001273
Use t,j, and b for their ages.
t = 4j or j = (1/4)t
t = (1/2)b or b = 2t
t + j + b = 39
Plug in and solve for t.
t + (1/4)t + 2t = 39
(13/4)t = 39
t = 12
From that
b= 24 and
j= 3