15. Find 30% of 20% of 60 16. A store has 600 books in the store. If 30 percent of these books are on sale, how many books are not on sale? 17. There are 27 students who arrive by school bus. These 27 students represent 60% of the class total. How many students in total are there in the class? 18. An item has a list price of $50. It sells at a discount of 15%. Find its selling price. 19. The regular price of an item is $60. The sales price is $48. What percent discount is being offered during the sale? 20. An item is selling for $400 after a 20 percent discount. What was the original selling price? 21. The price of an item rises from 60 cents to 90 cents. What is the percent increase of the price rise? 22. In how many ways can 4 students be seated in 4 seats? 23. How many different numbers of 3 different digits each can be formed using the digits 1, 2, 3, 5, 6, 8? 24. How many different numbers of 3 different digits each can be formed using the digits 2, 3, 4, 5, 7, 8, 9 if the last digit of the 3 digit number is to be an a) even digit b) odd digit