top of page
Brainteasers
Newsletter April 2025
If you have a 7-minute hourglass and an 11-minute hourglass, how can you boil an egg in exactly 15 minutes?
Hover cursor here to reveal answer
Answer: To boil the egg in exactly 15 minutes, follow these four steps.
Start both hourglasses as you start boiling the egg.
After the 7-minute hourglass runs out, turn it over to start it again.
Four minutes later, when the 11-minute hourglass runs out, turn the 7-minute hourglass again.
Wait for the 7-minute hourglass to run out, which will take another four minutes and get you to exactly 15 minutes of boiling time.
Adam Caar
Developer
I'm a paragraph. Click here to add your own text and edit me. It’s easy.
Previous Newsletter
My twin lives at the reverse of my house number. The difference between our house numbers ends in two. What are the lowest possible numbers of our house numbers?
Hover cursor here to reveal answer
Your house number is 19, your twin's house number is 91, the difference between the numbers is 72.
Adam Caar
Developer
I'm a paragraph. Click here to add your own text and edit me. It’s easy.
bottom of page