Question

A ship must be unloaded by two cranes in 12 hours. Both cranes worked for 8 hours and then one of them broke. The rest of the work was done by the other crane in 7 hours. How long would each crane take to do the entire job if it was working alone? Thank you!

Answer 1

8 hours x 2 cranes = 16 hours of total work

After one broke

7 hours x 1 crane = 7 hours of total work

16 + 7 = 23 hours

It would take 23 hours for one crane to do the whole job.

Answer 2

6 hours

Explanation: