Four members of one family have a combined age of 135 years.
Jeff is twice as old as his daughter Ann, while Trudy is 5 years younger than her husband, Jeff.
Harry is a third of his mother Trudy's age.
How old are each of the four members of this family?
Let Ann's age be A
Then Jeff's is 2A, Trudy's is 2A - 5, and Harry's is
We then get:
15A + 2A - 5 = 420 -------- Multiplying by LCD, 3
17A = 425
We then get: