Question Detail

Raju age after 15 years will be 5 times his age 5 years back, What is the present age of Raju

Answer: Option C

Explanation:

Clearly,
x+15 = 5(x-5)
<=> 4x = 40 => x = 10

1. Ages of two persons differ by 16 years. If 6 year ago, the elder one be 3 times as old the younger one, find their present age

12,28
14,30
16,32
18,34

Answer: Option B

Explanation:

Let the age of younger person is x,
Then elder person age is (x+16)
=> 3(x-6) = (x+16-6) [6 years before]
=> 3x-18 = x+10
=> x = 14.
So other person age is x + 16 = 30

2. Ratio of ages of three persons is 4:7:9, Eight years ago, the sum of their ages was 56. Find their present ages.

16,35,36
12,28,36
16,28,27
16,28,36

Answer: Option D

Explanation:

Let the present ages are 4x, 7x, 9x.
=> (4x-8) + (7x-8) + (9x-8) = 56
=> 20x = 80
=> x = 4

So their present ages are: 16,28,36

3. A man is 24 years older than his son. In two years, his age will be twice the age of his son. The present age of this son is

21 years
22 years
23 years
24 years

Answer: Option B

Explanation:

Let's Son age is x, then Father age is x+24.
=> 2(x+2) = (x+24+2)
=> 2x+4 = x+26
=> x = 22 years

4. Sachin is younger than Rahul by 7 years. If the ratio of their ages is 7:9, find the age of Sachin

23.5
24.5
12.5
14.5

Answer: Option B

Explanation:

If Rahul age is x, then Sachin age is x-7,
so (x-7)/x = 7/9
=> 9x-63 = 7x
=> 2x = 63
=> x = 31.5

So Sachin age is 31.5 - 7 = 24.5

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}