Algebra and Up:
Question: Decode the cipher to solve the problem.
VDOOB KDV WZR DSSOHV. WLPPB KDV ILYH DSSOHV. KRZ PDQB PRUH DSSOHV WKDQ VDOOB GRHV WLPPB KDYH?
Answer: 3 apples
Solution: Thsi is Caeser cipher - each letter has been shifted the same number of positions. One way to solve it is to look at the first word in the last sentence, which is a question. We can reason that KRZ nust be "who", "why", or "how" because those are the three-letter words that begin questions. If we test those words by shifting the letters, we find that the word is "how" and that shifting each letter 3 positions backward decodes the cipher. The problem decodes to "Sally has 2 apples. Timmy has 5 apples. How many more apples than Sally does Timmy have?" The answer is 3 apples.