Study guides › Level 6 · Master
Age puzzles
💡 The idea
Ages move together: every year, everyone gets one year older. So the gap between two people never changes.
🪜 The steps
- Find one person’s age now. Undo any “in 2 years” or “3 years ago” first.
- Use the gap or the “twice as old” to find the other age now.
- Only then move forward or back in time, if the question asks.
⚠️ Watch out
- Twice as old is about one moment. If A is twice as old as B now, A won’t be twice as old in 5 years.
- “Add up to” puzzles: take away the gap, then halve.
🎯 Try these
- Lee is 4 years older than Kim. In 3 years Kim will be 11. How old is Lee now?
- Two ages add up to 20. One is 6 years older. How old is the younger one?
Answers: 1) 12 (Kim is 8 now) 2) 7
This guide is also in the 10LogicQ app: tap “📖 Study guide” after a puzzle.