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

Ex Input:
Problem: a cistern 5 m long and 4 m wide contains water up to a depth of 1 m 25 cm . the total area of the wet surface is :

Ex Output:
42.5 m 2


Ex Input:
Problem: a train running at the speed of 72 km / hr crosses a pole in 9 seconds . find the length of the train .

Ex Output:
180 meter


Ex Input:
Problem: the average marks of a class of 12 students is 40 and that of another class of 28 students is 60 . find the average marks of all the students ?

Ex Output:

54.