Weights of two friends Ram and Shyam are in the ratio of 4 : 5. Ram’s weight increases by 10% and the total weight of Ram and Shyam together becomes 82.8 kg, with an increase of 15%. By what per cent did the weight of Shyam increase?	Choose the correct option.
A) 12.5 %  B) 17.5 %  C) 19 %  D) 21 %  E) none of these

Rationale: let the weights of ram and shyam be 4 x and 5 x . now , according to question , 4 x × 110 / 100 + shyam ? snewwt 4 x × 110100 + shyam ? s new wt = 82.8 . . . . . . . . ( i ) and 4 x + 5 x = 9 x + 115 / 100 = 82.8 . . . . . . . . ( ii ) from ( ii ) , x = 8 putting in ( i ) , we get shyam ’ s new wt = ( 82.8 – 35.2 ) = 47.6 % increase in shyam ’ s wt = ( 47.6 − 40 / 40 × 100 ) = 19 answer c
Answer: C