Answer:
He can process 45 engines in 2 hours.
Step-by-step explanation:
2 hours = 120 minutes
You can multiply 3 to 40 because 40x 3 = 120, but you have to do the same to 15, so 15 x 3 = 45.
Or you can divide the engines (15) by minutes (40) to find out how many engines can be processed per minute.
15/40 = 0.375 an engine per minute.
Then multiply that by 120, which is two hours in minutes.
0.375 x 120 = 45
