Answer:
Janine is 45, Paul is 51 , Brett is 17 and Amanda is 12 years old.
Explanation:
Let their ages be J (Janine's age), P , B and A.
Then we are given:
J = P - 6 (1)
P = 3B (2)
A = B - 5 (3)
J + P + B + A = 125 (4).
Using (2) to substitute in (4):
J+ 3B + B + A = 125 Now A = B - 5, so:
J + 4B + B - 5 = 125
J + 5B = 130 Now using (1) to substitute for J:
P - 6 + 5B = 130
P + 5B = 136 Using (2) to substitute for P:
3B + 5B = 136
8B = 136
B = 17.
So from (2): P =3*17 = 51.
From (3): A = B - 5 = 12.
and finally
J = P -6 = 45.