The task is to generate the correct answer for a given math problem.

Problem: a cycle is bought for rs . 900 and sold for rs . 1170 , find the gain percent ?
30 %

Problem: a sells a bicycle to b and makes a profit of 60 % . b sells the same bicycle to c at a profit of 25 % . if the final s . p . of the bicycle was rs . 225 , find out the cost price of the bicycle for a .
112.

Problem: two trains of equal are running on parallel lines in the same direction at 18 km / hr and 36 km / hr . the faster train passes the slower train in 36 sec . the length of each train is ?
25