Weights of two friends Ram and Shyam are in the ratio 4:5. If Ram's weight is increased by 10% and total weight of Ram and Shyam become 82.8 kg, with an increases of 15%. By what percent did the weight of Shyam has to be increased? Choose the correct choice from the following choices.
A) 19 % B) 10 % C) 21 % D) 16 % E) none

Rationale: "solution : given ratio of ram and shayam ' s weight = 4 : 5 hence , ( x - 15 ) / ( 15 - 10 ) = 4 / 5 or , x = 19 % . answer : option a"
Answer: A