Correct Answer - Option 3 : 70
Given,
Average age of A, B and C, 3 years ago = 45
Average age of A, B and C at present = 45 + 3 =48
Sum of ages of A, B and C (A + B + C) = 48 × 3 = 144
Given,
Average age of B and C, 4 years ago = 35
Average age of B and C at present = 35 + 4 = 39
Sum of ages of B and C (B + C) = 39 × 2 = 78
Age of A at present= (A + B + C) - (B + C)
= 144 - 78
= 66
Age of A after 4 years = 66 + 4 = 70 years.
So, the age of A, after 4 years is 70 years.
Hence, the correct answer is 70.