Answer:
Average per year flow rate = 1168 planes/year
Step-by-step explanation:
The flow rate is the amount of a substance that passes through an area per unit of time. In this case, the average flow rate per year of planes is the number of planes that undergo maintenance in the maintenance facility per year.
In order to calculate the average flow rate, let us first calculate the number of planes in each category of percentage maintenance:
Total number of planes = 365
2 preventive maintenance
40% of the planes = 40% of 365
= 0.4 × 365 = 146 planes
This means that 146 planes in this category are sent for routine maintenance twice within the year.
∴ flow rate for two routine maintenance through the year
= 146 planes × 2 = 292 planes per year
4 preventive maintenance per year
60% of 365
= 0.6 × 365 = 219 planes
This means that 146 planes in this category are sent for routine maintenance four times within the year.
∴ flow rate for four routine maintenance through the year
= 4 × 219 = 876 planes per year
∴ Total flow rate per year = 292 + 876 = 1168 planes/year