Please help This is hard

The last time i bought this product , it cost $20.00 but it looks like it cost 29. 60 today? what is the increase

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.)

The product of sin 30 degrees and sin 60 degrees is same as the product of