1. 1.6%

2. 30

3. 0.16 (Two fifths squared is four twenty fifths or 16 hundredths)

4. c

5. 324

6. Sam has 21 balls and Fred has 15 balls.
If Sam would give Fred 3 balls, they would have an equal number (i.e., 18 balls each).
If Fred would give Sam 3 balls, then Sam would have 24 balls and Fred would have 12 balls.

7. b

8. $128

9. a

10. 579 pages