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 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

Answer: Option A

Explanation:

Let Snehals age 6 years back = x.
Then, Sushils age 6 years back = 3x.
(5/3) * (X + 6 + 6) = (3X + 6 + 6)
So 5(x+ 12) = 3(3x+ 12),
so x=6.
Snehal Age = (x+ 6) years = 12 years

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

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

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