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
Thus

x = 22

answer:

Alice collect between week 5 and week 7, 22 stamps.

D. 22