Present age of father = 45 years
Present age of son = 15 years
(i) Required ratio = 45/15 = 3/1 = 3 : 1
(ii) 5 years ago (when son was 10 years old) age of father = 45 – 5 = 40 years and age of son = 15 – 5 = 10 years
Required ratio = 40/10 = 4/1 = 4 : 1
(iii) After 5 years, age of father = 45 + 5 = 50 years and, age of son = 15 + 5 = 20 years
Required ratio = 50/20 = 5/2 = 5 : 2
(iv) when father will be 60 years old (i.e. after 15 years) age of son = 15 + 15 = 30 years
Required ratio = 60/30 = 2/1 = 2 : 1