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).