Why 21 is the correct answer to this problem: Each packet of washing powder carries a token and four tokens canbe exchanged for a free packet. How many free packets will Ireceive if I buy 64 packets?

Over the past year, John has purchased 30 books. In how many ways can he pick four of these books and arrange them, in order, on his nightstand bookshelf? In how many ways can he choose four of these books to take with him on his vacation at the shore?

At Rosemont High School, 14 players are on the varsity basketball team, 35 players are on the varsity football team, and 7 of these players are on both teams. How many different individual players are on the two varsity teams?

Hector wants to place billboard advertisements throughout the county for his new business. How many ways can Hector choose 15 neighborhoods to advertise in if there are 30 neighborhoods in the county?

How many teaspoons are in 1 cup?

Susan bought 20 plants to arrange along the border of her garden. How many distinct arrangements can she make if the plants are comprised of 6 tulips, 6 roses, and 8 daisies?

Over the past year, John has purchased 30 books. a In how many ways can he pick four of these books and arrange them, in order, on his nightstand bookshelf? b In how many ways can he choose four of these books to take with him on his vacation at the shore?

Last year, at Haven's Pond Car Dealership, for a particular model of BMW, Jeep, and Toyota, one could purchase all three cars for a total of $140,000. This year, due to inflation, the same cars would cost $151,830. The cost of the BMW increased by 8%, the Jeep by 5%, and the Toyota by 12%. If the price of last year's Jeep was $7,000 less than the price of last year's BMW, what was the price of each of the three cars last year?

Laura gave birth to triplets weighing 3 pounds 3 ounces, 3 pounds 3 ounces, and 2 pounds 9 ounces. What was the total birth weight of the three babies?