TASK DEFINITION: The task is to generate the correct answer for a given math problem.
PROBLEM: Problem: a and b can do a piece of work in 7 days . with the help of c they finish the work in 5 days . c alone can do that piece of work in ?

SOLUTION: 30 days

PROBLEM: Problem: if one - third of one - fourth of a number is 18 , then 3 - tenth of that number is : a . 35

SOLUTION: 64.8

PROBLEM: Problem: a father and his son are waiting at a bus stop in the evening . there is a lamp post behind them . the lamp post , the father and his son stand on the same straight line . the father observes that the shadows of his head and his son ' s head are incident at the same point on the ground . if the heights of the lamp post , the father and his son are 6 metres , 1.8 metres and 0.9 metres respectively , and the father is standing 2.1 metres away from the post , then how far ( in metres ) is the son standing from his father ?

SOLUTION:
0.45