In this “episode”, there are two different puzzles, both of them are measuring a specific duration of time with a few “timers”.
Here is the first one:
You have two lengths of fuse, each will burn for exactly one hour. But the fuses are not necessarily identical and do not burn at a constant rate. There are fast burning sections and there are slow burning sections. How do you measure 45 minutes using the fuses and a lighter?
Source: How Would you move Mount Fuji, by William Poundstone; Puzzle #50
Target: 12+ years
Here is the second one:
You have two timers, one that goes off after 7 minutes and another one that goes off after 11 minutes. You need to boil an egg for exactly 15 minutes. How would you measure 15 minutes using the two timers?
Source: Mathematical Cirlces (Russian Experience) by Dmitri Fomin, Sergey Genkin and Ilia Itenberg (Page 67, Puzzle #18)
Target: 8+ year