Puzzle This By Michael H. Pryor
MAKE’s favorite puzzles. (When you’re ready to check your answers, visit makezine.com/20/aha.)
Tanks A Lot
Four kids started aquariums in their houses. They each had one fish and one invertebrate in their tanks.
Unfortunately, they also each had a different problem with their tanks. One tank had lighting issues, another
had pH problems, one couldn’t maintain the right temperature, and the other one had an algae outbreak.
The kids each fed their tanks at different times of day (morning, afternoon, evening, and night).
Figure out who owned which tank and had which problem; the fish and the invertebrate that lived there;
and the time of day that the owners fed their tanks.
1. The aquarium that was fed in the evening had an
algae bloom problem. Victor did not feed his tank in
Illustration by Roy Doty
2. The tank with temperature problems had an urchin
in it. Ruth did not feed her tank in the evening.
3. The lionfish did not have a pH problem in its tank.
The clownfish tank had lighting issues.
4. The anemone’s tank was not fed at night.
5. Victor, who did not have a clownfish, had a clam in
his tank. Aviva’s scooter blenny was not in the tank
with the algae problem.
6. Michael, who did not have a clownfish, fed his
tank in the afternoon. The blue tang and the shrimp
lived in the same tank, but they did not eat in the
Michael Pryor is the co-founder and president of Fog Creek Software. He runs a technical interview site at techinterview.org.