Question Detail

The ratio between the present ages of P and Q is 6:7. If Q is 4 years old than P, what will be the ratio of the ages of P and Q after 4 years

Answer: Option A

Explanation:

Let P age and Q age is 6x years and 7x years.
Then 7x - 6x = 4 <=> x = 4

So required ratio will be (6x+4): (7x+4) => 28:32 => 7:8

1. The ages of two persons differ by 20 years. If 5 years ago, the elder one be 5 times as old as the younger one, their present ages (in years) are respectively

20,20
20,10
25,15
30,10

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

2. 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 D

Explanation:

Sachin's age today = 30 years.
Sachin's age 10 years back = 20 years.
Ajay's age 10 years back = 10 years.
Ajay's age today =20 years

3. Ten years ago, P was half of Q in age. If the ratio of their present ages is 3:4, what will be the total of their present ages

Answer: Option A

Explanation:

Let the present age of P and Q be 3x and 4x respectively.
Ten years ago, P was half of Q in age
=> 2(3x – 10) = (4x – 10)

=> 6x – 20 = 4x – 10

=> 2x = 10

=> x = 5

4. Six years ago, the ratio of the ages of Kunal and Sagar was 6:5, Four years hence, the ratio of their ages will be 11:10. What is Sagar age at present

10 years
12 years
14 years
16 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

5. Tanya's grandfather was 8 times older to her 16 years ago. He would be 3 times of her age 8 years from now. What was ratio of ages of Tanya and her grandfather 8 years ago.

11:50
11:51
11:53
11:54

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}