Answer:
27. C
28. D
Step-by-step explanation:
The average of all grades in his fencing class, including the upcoming one, (all grades summed up divided by the amount of grades) must be equal to 86 (percent), hence C is the right answer for 27.
Solving this equation gives:

So D is the right answer for 28.
The step 2 because 3 is not multiplying the 1 only the x in the bracket
Answer:
67 degrees
Step-by-step explanation:
If angle a is 113 degrees, angle d will be 113 degrees subtracted from 180 degrees. Because angles in a straight line adds up to 180 degrees.
Answer:
500
20%=100
100%= 5×100=500 (cause 100 is 20%, and in 100% is five 20% so...)