Sachin was twice as old as Ajay 10 years back. How old is Ajay today if Sachin will be 40 years old 10 years hence

Answer: Option C

Explanation:

Let sons age = x years. Then fathers age = (45 - x)years.
(x—5)(45—x—5) = 4(45- x - 5) hence (x—5) = 4 so x = 9
Their ages are 36 years and 9 years.

Answer: Option B

Explanation:

Let A's age 10 years ago = x years.
Then, B's age 10 years ago = 2x years.
(x + 10) / (2x+ lO) = 3/4
=> x = 5.
So, the total of their present ages =(x + 10 + 2x + 10)
= (3x + 20) = 35 years.

Answer: Option D

Explanation:

Let six years ago the age of Kunal and Sagar are 6x and 5x resp.
then,
\begin{aligned}
=> \frac{(6x+6)+4}{(5x+6)+4} = \frac{11}{10}
\end{aligned}
\begin{aligned}
<=> 10(6x+10) = 11(5x+10)
\end{aligned}
\begin{aligned}
<=> 5x = 10 => x = 2
\end{aligned}

So Sagar age is (5x+6) = 16

Answer: Option C

Explanation:

Let, Tanya age 16 years ago = x,
Grandfather's age 16 years ago = 8x.

8 years from now, 3(x+16+8) = (8x+16+8)
=> x = 48/5

8 years ago ratio was:

\begin{aligned}
=> \frac{x+8}{8x+8} = \frac{\frac{48}{5}+8}{8 \times \frac{48}{5}+8}
\end{aligned}

\begin{aligned}
=> \frac{88}{424} = \frac{11}{53}
\end{aligned}

Answer: Option D

Explanation:

Let their ages be x and (x + 20) years.
5 (x - 5) = (x + 20 - 5) or 4x = 40 or x = 10.
Their present ages are 30 years and 10 years