Please explain answers!

DGA Tile manufactures ceramic flooring tiles. DGA's annual fixed costs are $740,000. The variable cost of each tile is $0.25, and tiles are sold for $6.50. DGA has a combined state and federal tax rate of 30 percent. Required: a) How many tiles does DGA need to make and sell each year to eam an after-tax profit of $85,000 ? b) DGA must pay 10 percent of before-tax profits as a royalty payment on its founder. Now how many tiles must DGA make and sell to generate $85,000 after taxes? (Assume the royalty payment is not a tax-deductible expenses.)