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

Input: Consider Input: Problem: the speed of a car is 85 km in the first hour and 45 km in the second hour . what is the average speed of the car ?

Output: 65 kmph

Input: Consider Input: Problem: what is the sum of natural numbers between 30 and 100

Output: 4615

Input: Consider Input: Problem: a train 250 m long , running with a speed of 50 km / hr will pass a tree in ?
Output: 18 sec