You have two ropes.
Each takes exactly 1 hour to burn — but unevenly.
How do you measure exactly 45 minutes?

Question

Accepted Answer

Light rope A at both ends and rope B at one end — simultaneously. When A finishes (30 min), light B’s other end. B finishes 15 min later. Total: 45. — “Burns unevenly” is a red herring. Burning a rope from both ends always halves its time — no matter how lumpy the burn. The trick was right in your hands; you just had to set them on fire.

You have two ropes. Each takes exactly 1 hour to burn — but unevenly. How do you measure exactly 45 minutes?