Machine A can make 350 widgets in 1 hour, and machine B can make 250 widgets in 1 hour. If both machines work together, how much time will it take them to make a total of 1000 widgets?
A.1 hour and 20 minutes
B.1 hour and 24
C.1 hour and 30 minutes
D.1 hour and 30 minutes
E.1 hour and 40 minutes
我的答案:
Machine A can make 350 widgets in 1 hour, and machine B can make 250 widgets in 1 hour. If both machines work together, how much time will it take them to make a total of 1000 widgets?