Alice collected stamps for 7 weeks. she counted the number of stamps in her collection every week. by week 2, there had been 7 stamps collected. how many stamps did alice collect between week 5 and week 7? a. 5 b. 6 c. 17 d. 22

What we can do to solve this problem is the following rule of three:
 2 weeks ---> 7 stamps
 7 weeks ---> x
 Clearing x we have:
 x = (7/2) * 7 = 24.5
 The other rule of three is:
 2 weeks ---> 7 stamps
 5 weeks ---> x
 Clearing x we have:
 x = (5/2) * (7) = 17.5
 You have the following inequality
 17.5 <x <24.5
 Thus
 x = 22
 
 Alice collect between week 5 and week 7, 22 stamps.
 D.22