The ratio between the presents of the A and B is 6:7. If B is 4 years older than A, what will be the ratio of the ages of A and B after 4 years?  Choices: A) 1 : 2 B) 9 : 11 C) 7 : 8 D) 6 : 7 E) 3 : 4

Rationale: let a and b ages will be 6 x and 7 x 7 x - 6 x = 4 x = 4 required ratio = 6 x + 4 : 7 x + 4 = 28 : 32 = 7 : 8 answer is c
Answer: C