In this task, you need to answer the given multiple-choice question on the physics. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Input: Consider Input: Problem: three pipes of same capacity can fill a tank in 8 hours . if there are only two pipes of same capacity , the tank can be filled in . 
Options: a ) 11 hours , b ) 12 hours , c ) 15 hours , d ) 16 hours , e ) 17 hours

Output: b


Input: Consider Input: Problem: calculate the speed of a boat in still water ( in km / hr ) if in one hour , the boat goes 10 km / hr downstream and 4 km / hr upstream . 
Options: a ) 7 kmph , b ) 8 kmph , c ) 9 kmph , d ) 7 kmph , e ) 6 kmph

Output: a


Input: Consider Input: Problem: jane makes toy bears . when she works with an assistant , she makes 80 percent more bears per week and works 10 percent fewer hours each week . having an assistant increases jane ’ s output of toy bears per hour by what percent q ? 
Options: a ) 20 % , b ) 80 % , c ) 100 % , d ) 180 % , e ) 200 %


Output: c