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

[Q]: Problem: a is half good a work man as b and together they finish a job in 14 days . in how many days working alone b finish the job ?
[A]: 21


[Q]: Problem: what is the sum of the odd integers from 55 to 75 , inclusive ?
[A]: 71


[Q]: Problem: a train covers a distance of 12 km in 10 minutes . if it takes 4 seconds to pass a telegraph post , then the length of the train is
[A]:
80 m