Problem:
Each morning of her five-day workweek, Jane bought either a 50-cent muffin or a 75-cent bagel. Her total cost for the week was a whole number of dollars. How many bagels did she buy?
Answer Choices:
A. 1
B. 2
C. 3
D. 4
E. 5
Solution:
Make a table for the cost of the muffins and bagels:
Cost of Muffins0⋅0.50=0.001⋅0.50=0.502⋅0.50=1.003⋅0.50=1.504⋅0.50=2.005⋅0.50=2.50Cost of Bagels5⋅0.75=3.754⋅0.75=3.003⋅0.75=2.252⋅0.75=1.501⋅0.75=0.750⋅0.75=0.00Total Cost3.753.503.253.002.752.50
The only combination which is a whole number of dollars is the cost of 3 muffins and (B)2 bagels.
The problems on this page are the property of the MAA's American Mathematics Competitions