instruction:
The task is to generate the correct answer for a given math problem.
question:
Problem: a and b can together finish a work in 40 days . they worked together for 10 days and then b left . after another 15 days , a finished the remaining work . in how many days a alone can finish the job ?
answer:
2


question:
Problem: tourist purchased a total of 30 travelers checks in $ 50 and $ 100 denominations . the total worth of the travelers checks is $ 1800 . how many checks of $ 50 denominations can he spend so that average amount ( arithmetic mean ) of the remaining travelers checks is $ 100 ?
answer:
2


question:
Problem: a train speeds past a pole in 22 seconds and a platform 140 m long in 33 seconds . its length is ?
answer:

280