a) 20 & 75 years

b) 15 & 80 years

c) 25 & 70 years

d) 30 & 65 years

correct answer is: d) 30 & 65 years

**Explanation**

Let, Son present age is ‘x’

Then, father present age is =\ \left(95\ -\ x\right)

\therefore 10 years ago, son age was =\left(x\ -\ 10\right)

and, 10 years ago, father age was =\ \left(95\ -\ x\right)\ -\ 10

10 years ago the ratio of their age was 11 : 4

According to the question,

\left(95\ -\ x\right)\ -\ 10\ ∶ \left(x\ -\ 10\right)\ =\ 11\ ∶\ 4

\rightarrow\ \frac{\left(95\ -\ x\right)\ -\ 10}{\left(x\ -\ 10\right)}\ =\ \frac{11}{4}

\rightarrow\ \frac{85\ -\ x}{x\ -\ 10}\ =\ \frac{11}{4}

\rightarrow11\left(x\ -\ 10\right)\ =\ 4\left(85\ -\ x\right) _{[cross multiply]}

\rightarrow\ 11x\ -\ 110\ =\ 340\ -\ 4x

\rightarrow\ 11x\ +\ 4x\ =\ 340\ +\ 110 _{[interchange]}

\rightarrow\ 15x\ =\ 450

\rightarrow\ x\ =\ \frac{450}{15}

\rightarrow\ x\ =\ 30

\therefore Son present age is 30 years.

And, father present age is \left(95\ -\ 30\right) years

=\ 65 years.**Ans:** Son present age is 30 years,

Father present age is 65 years.