Answer:
They would be done by 2 : 18 AM
Step-by-step explanation:
Key Information:
- Stacey starts at 2 PM peeling 20 potatoes per hour
- Rob starts at 3 PM peeling 30 potatoes per hour
- James starts at 4 PM peeling 40 potatoes per hour
At 5pm;
Stacy would have worked for 3 hours and would have peeled ( 3 * 20 = 60 potatoes)
Rob would have worked for 2 hours and would have peeled ( 2 * 30 = 60 potatoes)
James would have worked for an hour and would have peeled ( 1 * 40 = 40 potatoes)
Total number of potatoes peeled at 5pm = 60 + 60 + 40 = 160 potatoes
Potatoes left = 1000 - 160 = 840 potatoes.
The new peeling rate for three of them combined is (20 + 30+ 40 ) = 90 potatoes per hour.
Rate = potatoes left / time;
Time = Potatoes / Rate
Time = 840 / 90 = 9.3 hours = 9 hours 18 minutes
Total time taken = 9 hours 18 minutes + 3 hours = 12 hours 18 minutes
They would be done by 2 : 18 AM
