I would guess it would be
7 and -7
2 2/3 cups of sugar if she wants to make 24 muffins
A) When the relation is inverse, the product of the two related values is a constant. Here we have
n·c = 4·312
n·c = 1248 . . . . an equation relating n and c
You can rearrange this to
c = 1248/n
B) Using 6 for n, we have
c = 1248/6 = 208
The cost per person decreases from 312 to 208, so decreases by $104.
