IBPS SO Prelims Exam Model Paper 8

Let the present age of father and mother be A and B years respectively.
Let the present age of son be C years.
From statement I:
(A – 5) : (B – 5) = 7 : 6
⇒ 6A – 30 = 7B – 35
⇒ 7B – 6A = 5
From statement II:
B + C = 56
From statement III:
(A + 5) + (C + 5) = 71
⇒ A + C = 61
Solving all three,
A – B = 5
⇒ A = 5 + B
Now, 7B – 6 × (5 + B) = 5
⇒ 7B – 30 – 6B = 5
⇒ B = 35 years
⇒ C = 21 years
⇒ A = 40 years
Required difference = 40 – 21 = 19 years
∴ Using all three statements we can answer the question.