Celine goes to the book fair where paperback books are $2 and hardback books are $4.50. Celine buys three paperback and 5 hardback books. How much change will Celine receive if she has $35?

7. Equation:

8. Solve:

Suppose you are choosing a 6-digit personal access code. this code is made up of 4 digits chosen from 1 to 9, followed by 2 letters chosen from a to z. any of these digits or letters can be repeated. find the total number of personal access codes that can be formed. 492,804 341,172 39,917,124 4,435,236