1.  10 yr before, the ratio of ages of A and B was 13 : 17. After 17 yr from now, the ratio of their age will be 10 : 11. the present age of B is :
A. 23 yr
B. 40 yr
C. 27 yr
D. 44 yr
E. None of the above

Answer: Option C

Explanation:

Let the age of A and B 10 yr before were 13x yr and 17x yr, respectively.

Then, present age of A = 13x + 10
and present age of B = 17x + 10

According to the question,

Then, 13x + 10 + 17 = 10
17x + 10 + 17 13

  13x + 27 = 10
17x + 27 11

143x + 297 = 170x + 2700

27x = 27

x = 1

Hence, present age of B = 17 x 1
                                     = 27 yr