Question Detail

In 10 years, A will be twice as old5as B was 10 years ago. If A is now 9 years older than B, the present age of B is

Answer: Option C

Explanation:

Let B's age = x years.
Then, As age = (x+ 9) years.
(x+9+10)=2(x—10)
hence x=39.
Present age of B = 39 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. 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 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

4. The total age of A and B is 12 years more than the total age of B and C. C is how many year younger than A

Answer: Option B

Explanation:

Given that A+B = 12 + B + C
=> A – C = 12 + B – B = 12
=> C is younger than A by 12 years

5. Which of following statements are required to answer the Actual age of Abhinav ?
1. Five years ago, Abhinav's age was double that of his son's age at that time.
2. Present ages of Abhinav and his son are in the ratio of 11 : 6 respectively.
3. Five years hence, the respective ratio of Abhinav age and his son's age will become 12 : 7.

1 and 3
2 and 3
Any two of three
None of three

Answer: Option C

Explanation:

From 2nd we get, Present ages of Abhinav and his son is 11x and 6x,

From 1st we get, Abhinav's present age = 2 * Son's age

From 3rd we get, 5 years hence, Abhinav age / Son's age = 12 / 7

From clearly we can get Abhinav age from any of two equations.