Question

Rajani's mother's age is twice that of Rajani. Rajani's mother's husband age is 10 years more than her mother's age. Rajani's age along with her father and mother's age put together is 160 years. What's her father's age?

• A. 65
• B. 70
• C. 75
• D. 80

Answer 1

Answer: (B)

70

Answer 2

Let's Rajani's age = $R$ and her mother's age = $M$,and her father's age=$F$.

Acc. to Ques:
$M = 2R$ (Rajani's mother's age is twice that of Rajani)
$F$ = $M + 10$.
So, total age =$R + M + F = 160$.

⇒$R + M + M + 10 = 160$

$R + 2(2R) + 10 = 160 \quad \text{(substituting } M = 2R\text{)}$
$5R + 10 = 160$
$5R = 150$
$R = 30$
So, $M=2R=2\times30=60$

So, Rajani's father's age is =$M+10=70$

Therefore, The correct option is (B).