Here’s a retail-related puzzle based off of a logic problem in George J. Summers’ Test Your Logic: 50 Puzzles in Deductive Reasoning.
“Avon, Bertrand, Celia, and Delia each wanted to buy their friend a small present at Eureka.
1. The four tweens, each of whose coins totaled one dollar, had the same number of silver coins.
2. Avon had exactly three quarters, Bertrand had exactly two quarters, Celia had exactly one quarter, and Delia had no quarters.
3. The four tweens had to pay the same amount; three paid the exact amount, but the fourth required change.
Who required change?
Note: silver coins may be nickels, dimes, quarters, or half dollars.”
And yes, we do have great little puzzles for under $1, including Japanese erasers, foam tangrams, and take-apart puzzles.