Lizzy: Tony loved to solve difficult pen and paper puzzles. He did a warm-up puzzle that only took 10 minutes and after that he did 2 puzzles that each took 3 times as long. How long did he spend solving puzzles?.
Me: Hmmm, let me think. I think this is the detailed solution:
Each of the long puzzles took 3 * 10 = 30 minutes to solve. So he spent 30 * 2 = 60 minutes solving them. That means he spent 60 + 10 = 70 minutes solving puzzles. Final answer: 70.