Subject: mathqa
Question: one pump drains one - half of a pond in 1 hours , and then a second pump starts draining the pond . the two pumps working together finish emptying the pond in one - half hour . how long would it take the second pump to drain the pond if it had to do the job alone ?
Option: 
A: 3 hours
B: 6 hours
C: 1.2 hour
D: 5 hours
Answer: A