Question

A store sells boxes of 6 muffins for $4 each and single muffins for $1 each. Mrs. Kim needs exactly 20 muffins. What is the LEAST amount she can spend?
A. $20
B. $14
C. $16
D. $12

Answer 1

Let b be number of 6-packs and s singles: 6b + s = 20, cost = 4b + s.

Try b = 0,1,2,3:
- b=0 → s=20 → cost = 20
- b=1 → s=14 → cost = 18
- b=2 → s=8 → cost = 16
- b=3 → s=2 → cost = 14

Minimum is $14 (3 boxes and 2 singles). Answer: B.