Here's a new mentalfloss.com Brain Game Think Thursday challenge for your consideration. Enjoy!

What's the missing number in the sequence below?

3, 7, 8, ?, 50, 60

Here is the ANSWER.

THE ANSWER:

40.

They're all the numbers that can be spelled with exactly five letters: three, seven, eight, forty, fifty, sixty.

Thanks for playing! Tomorrow, it's Free-for-all Friday.