Difficulty: Fun

On my bookshelf, my favourite book is the third from the left, and it’s the seventh from the right.

How many books are there on that shelf?

Scroll down or click for a hint, or the answer!

brain icon

Brainteaser hint

Try drawing the shelf or go grab some books to try it out!

brain icon

Brainteaser answer

There are 2 books to the left of my favourite book, and 6 books to its right. And my book also counts!

2 + 1 + 6 = 9

So there are 9 books on the shelf.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

By submitting this form, you give CSIRO permission to publish your comments on our websites. Please make sure the comments are your own. For more information please see our terms and conditions.

Why choose the Double Helix magazine for your students?

Perfect for ages 8 – 14

Developed by experienced editors

Engaging and motivating

*84% of readers are more interested in science

Engaging students voice