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

Input: Consider Input: Problem: a train running at the speed of 70 km / hr crosses a pole in 9 sec . what is the length of the train ?

Output: 175 m


Input: Consider Input: Problem: a and b together can complete work in 6 days . a alone starts working and leaves it after working for 4 days completing only half of the work . in how many days it can be completed if the remaining job is undertaken by b ?

Output: 12


Input: Consider Input: Problem: the average age of students of a class is 15.8 years . the average age of boys in the class is 16.7 years and that of the girls is 15.4 years . the ration of the number of boys to the number of girls in the class is :


Output: 4 :