Question 517214
Present age of Jim = 50
Present age of Diana = 20

Let
x years ago Jim was three times that of his daughter



x years ago Jim's age = 50-x
x years ago Diana's age = 20-x

x years ago the age of Jim was three times that of his daughter

50-x=3(20-x)
50-x=60-3x
3x-x=60-50
2x=10
x=10/2
x=5

Fiver years ago Jim's age was three times that of Diana's
Diana was 15 and Jim was 45 (which is 3 times of 15)