The present age of A is 40% less than B and the present age of B is 25% less than C. Four years hence, the sum of age of B and C will be 78 years. Find the present age (in years) of A.

Correct option is C

Let present age of C =4x
So, present age of B = 75% of 4x =3x
So, present age A = 60% of 3x =1.8x
ATQ (4x+3x) + 8 = 78
7x = 70
x = 10
So, present age of A = 1.8 ×10=18 years