This riddle makes the rounds from time to time and I think it’s a great interview question to test how people think.

A boy was playing with a book and tore out the pages 7, 8, 100, 101, 222 and 223. How many pages were torned out?

This riddle has been trending on Facebook, Twitter and Whatsapp. If you’re ready to find out the answer, keep reading.

A

B

C

ANSWER:
The first instinct would be to assume that the boy tore out 6 different pages, but it’s a little more complex than that. In a book, there are actually two numbered pages on each sheet of paper. The pages are printed on both sides, and each one has an odd and an even number. The odd pages will almost always be on the right hand side while the even pages will be on the left hand side. Therefore, the first page in a book will actually be numbered 1-2 and the second page will be numbered 3-4, on and on.

When reading the riddle, we can see that the boy ripped out pages 7 and 8, which are actually both sides of the same page. He then ripped out 99-100 and 101-102 which are the second and third pages he ripped out. 221-222 is the fourth page the boy ripped out and 223-224 is the fifth page.

The answer is that the boy ripped out 5 pages.