Problem: 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 ? 
Options: a ) 12.5 % , b ) 17.5 % , c ) 19 % , d ) 21 % , e ) none of these
c