Algebratown is 90km away from Numberville.
Doris drives from
Algebratown to Numberville
at 60 km/h, and then drives
back at 30km/h.
(a) Find the total time taken.
(b) Find her average speed.

2. using calculations based on a perpetual inventory system, determine the inventory balance altira would report in its august 31, 2021, balance sheet and the cost of goods sold it would report in its august 2021 income statement using the average cost method. (round "average cost per unit" to 2 decimal places.)