plz solve both

Illustration 18: Mr. Young has 1,50,000 investment in a business. He wants a 15% profit on his money. From an analysis of recent cost figures he finds that his variable cost of operating is 60% of sales; his fixed costs are 75,000 per year. Show supporting computations for each answer. (a) What sales volume must be obtained to break-even? (b) What sales volume must be obtained to his 15% return on investment? (c) Mr. Young estimates that even if he closed the doors of his business he would incur 25,000 expenses per year. At what sales would be better off by locking his sales up