Question Detail

The sum of the ages of a father and son is 45 years. Five years ago, the product of their ages was four times the fathers age at that time. The present age of father and son

34,11
35,10
36,9
40,5

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.

1. The sum of the ages of a father and son is 45 years. Five years ago, the product of their ages was four times the fathers age at that time. The present age of father and son

34,11
35,10
36,9
40,5

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.

2. 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

3. Average age of A and B is 24 years and average age of B, C and D is 22 years. The sum of the ages of A, B, C and D is

90
98
120
Data is not adequate

Answer: Option D

4. A person's present age is two-fifth of the age of his mother. After 8 years, he will be one-half of the age of his mother. How old is the mother at present

Answer: Option B

Explanation:

Let the mother's present age be x years.
Then, the person's present age = (2/5 x) years.

=> (2/5 x + 8/2) = 1 (x + 8)
=> 2(2x + 40) = 5(x + 8)
=> x = 40

5. 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