20 points
One pump can fill a tank of water in 4 hours. A second tank can fill the same tank in 3 hours. If both pumps are used together, how long will it take to fill the tank?

7/12 hours
3/4 hours
12/7 hours
4/3 hours

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.)