Two numbers are in the ratio of 7 : 4. If each number is increased by 12, then the ratio becomes 3 : 2. The sum of the numbers is:

66

Here,

A : B

7 : 4

After adding 12 to both numbers,

A : B

3 : 2

To compare both, we multiply final ratio with 3,

⇒ (3 : 2) x 3 = 9 : 6

⇒ 6 - 4 = 2 units = 12

⇒ 1 unit = 6

⇒ Sum of initial numbers = (7 + 4) x 6 = 11 x 6 = 66.