Question

the present age of A and B are in the ratio 4:5 and after 5 years they will be in the ratio 5:6 what will be present age of A

Answer 1

Ration of present ages=4/5
 Let Present age of A = 4k
      and Present age of B= 5k
                                 
                     we are given, 4k+5/5k+5=5/6
                                      So, 24k+30=25k+25
                                             k=5

                           So Present age of A= 4k= 4*5=20 yrs.
                         and, Present age of B=5k=5*5=25 yrs.

Answer 2

I think the answer is 30 because before 5 years,if A and B was 20 and 25 years old their ratio will be 4:5 and after 5 years they'll be 25 and 30 years old and ratio will be 5:6.