Time for another adventure in viral math. This problem was originally spotted by the Daily Mail and has baffled hundreds of thousands of people on Facebook. Can you solve it?

There are two possible answers. If you can figure out the first one, give yourself a pat on the back — and don’t feel bad if you can’t come up with the second solution. When Daily Mail shared the problem, only one in 1,000 people managed to get the second possible answer.

Solution #1

Start with the first line: 1+4 = 5. Makes sense. Off to a good start.

Line two: 2+5 = 12. Wait a minute. 2+5 = 7. But if you add the 5 from the first line, we get 12.

Let’s see if that works with the third line. 3+6 doesn’t equal 21. But if we add the sum from the line above, 3+6+12 = 21.

In line four, 8+11 = 19. Add the 21 from line three and we get 40.

One possible answer is 40.

Solution #2

Remember, if your answer was 40, take a bow. That’s a win in our book. But there’s a second possible answer.

What if, instead, you looked at the first line as 1 + (1*4) = 5? Then in the second line, 2 + (2*5) = 12. In the third line, 3 + (3*6) = 21.

For the fourth line, 8 + (8*11) = 96.

A second possible answer is 96.

If you got 96, pat your back with both hands. A big patting hug.


Up for another?

Here’s the answer.