The ratio of difference between the present age of A and B to the present age of B and C is 6:1. 6 years hence, the ratio between the age of A and C is 21:11. If the present age of B is 25% less than the present age of
C. find the sum of the present age of A, B, and C? 

Let the present age of A, B and C be a, b, and c respectively, As per the question  b=(1-25/100)c b/c = 3/4 b = (3/4)c Ratio of the present age of B And C is 3:4  ((a-b))/((c-b) )=6/1 = (a-b)=6(c-b) a=(6c-(15/4)c)= a/(c)=9/4 Therefore, the ratio between present age of A, B, and C is 9:3:4. As per the question  6 years hence ratio of age of A and C is 21: 11. (9x+6)/(4x+6) = 21/11 99x + 66=84x+126  15x=60  x=4  The present age of A, B, and C are 36 years, 12 years, and 16 years. Sum of A, B, and C = 36 + 12 + 16 = 64 years