Riddle: Mary was working in a chemistry lab with a mixture of chemicals that was 90% water and weighed 20 pounds. After returning to the lab from a weekend break, she calculated the mixture was now 50% water. How much does the mixture now weigh? For purposes of this puzzle, assume the non-water part of the mixture was not affected by evaporation.
Rating: 100%
Rating: 100%
Rating: 67%
Riddle: A circle of stones, never in rows. Stacked one on the other, mystery it sows. What is it?
Rating: 100%
Rating: 100%