Correct option is D
Given:
A is 9 years older than B.
In 10 years, A will be twice as old as B was 10 years ago.
Solution:
Let the present age of B be x. Then A = x + 9.
In 10 years, A will be (x + 9 + 10) = x + 19 years.
B was x - 10 years old, 10 years ago.
Given, A's age in 10 years = 2 * (B's age 10 years ago).
=> x + 19 = 2 * (x - 10).
=> x + 19 = 2x - 20.
=> x = 39.
Thus, A's present age = x + 9 = 48 years.
