12
18
24
30
Number of
books
Price ($)
B
50
56
62
66
12
24
48
96
Number of
books
Price ($)
C.
50
150
200
250
12
36
48
60
Number of
books
Price ($)
D
50
150
200
250
120
180
240
300
Number of
books
Price
($)
120
156
220
460