In this task, you need to answer the given multiple-choice question on the gain. Gain is the value by which to multiply the input. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Input: Consider Input: Problem: a man can row his boat with the stream at 18 km / h and against the stream in 8 km / h . the man ' s rate is ?
Options: a ) 5 kmph , b ) 2 kmph , c ) 7 kmph , d ) 8 kmph , e ) 3 kmph

Output: a

Input: Consider Input: Problem: what sum of money will produce rs . 70 as simple interest in 4 years at 4 1 / 2 percent ?
Options: a ) 263 , b ) 500 , c ) 388.9 , d ) 368 , e ) 339

Output: c

Input: Consider Input: Problem: a trader bought a car at 20 % discount on its original price . he sold it at a 70 % increase on the price he bought it . what percent of profit did he make on the original price ?
Options: a ) 17 % , b ) 72 % , c ) 12 % , d ) 82 % , e ) 36 %
Output: e