Question Detail

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

1. 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

2. 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

3. 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

4. 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.

5. 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