Answer:
14. 14.86 (simple subtraction)
15. 4 dollars (156/39 = 4)
18. 49 (36,39,44,48,50,50,54,55 so mean of 48 and 50 is 49)
19.14 (3.5/0.25)
20. A(understanding question contex)
25. 3a + 3b or C (add all the a's and b's together)
26. 5 (Divide apples by 3)
28.C(multiply all the sides together)
29. A (12/7 is fraction form of 12 : 7)
30. C (rate is 20 so 6 * 20 = 120)
31. D
Hoped this helped, this took a while to do :)