Average parts produced per hour

A production team made 510 parts in the first 3 hours of a day, then 186 parts per hour for the next 5 hours. On average, how many parts did they make per hour that day?

Step-by-step

1. 186 × 5 = 930
   Find the total produced in the last 5 hours
2. 510 + 930 = 1440
   Find the total produced in the whole day
3. 3 + 5 = 8
   Find the total number of working hours
4. 1440 ÷ 8 = 180
   Divide total output by total time to get the hourly average

Why it works

Total output is 1440 parts over 8 hours, and 1440 ÷ 8 = 180 parts per hour.

Common mistakes

• Averaging 510 and 186 directly, ignoring that the two periods have different lengths.
• Dividing by 3 or by 5 instead of by the total time of 8 hours.
• Using the total 1440 as the answer instead of the per-hour average.