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.
Answer:
5
Step-by-step explanation:
3/(3/5) = 5
That's too much. you should just put it separate. most won't want to answer.
n has less than 75 copies
sold 12
so add the 12 back
n had less than 87 copies in the beginning of the day
:)
Answer:
13
Step-by-step explanation:
533/41