If 4 men can reap a field in 5 days working 9 hours a day, in how many hours can 10 men reap the same field working 3 days?
A5
B3
C6
D7
A5
B3
C6
D7
Related Questions:
A can do th of a work in 4 days and B can do th of the same work in 5 days. In how many days they can finish the work, if they work together?