5: You need to turn 8 into a fraction over 8. 8*3 = 24, so 24/3. There are 24 1/3 cups in 8.
6: She can fill more than 8 tortillas
8: This one ties back to #5, with the 24/3. You divide 24 by 2, so 12. You'll have 12 groups with 24 pieces in total. (Circle 12 groups of 2)
9: 8 / (2/3) is the same as 8*3/2 which equals 12. 12 tortillas.
10: To get a common denominator for 12/8 and 3/4, you can convert 3/4 to 6/8 [3/4 = 6/8] And since 6 is half of 12, 12/8 - 6/8 = 6/8. Mike can only fill 2 glasses
Hope it helps :D