instruction:
The task is to generate the correct answer for a given math problem.
question:
Problem: a can do a work in 15 days and b in 20 days . if they work on it together for 5 days , then the fraction of the work that is left is
answer:
5 / 12


question:
Problem: two numbers are in the ratio 3 : 5 . if 9 be subtracted from each , they are in the ratio of 1 : 2 . the first number is :
answer:
a ) 27


question:
Problem: if 4 men working 10 hours a day earn rs . 800 per week , then 9 men working 6 hours a day will earn how much per week ?
answer:

rs 1080