Don’t forget to have fun with numbers, with this riddle you can have some quality time with your friends and family.

Below you will see a series of equations, where the operator is used differently. Find the usage of the operator in the first 3 equations and then find the missing number in the last equation.

If,

1 + 4 = 5

2 + 5 = 12

3 + 6 = 21

Then,

5 + 8 = ?

So were you able to solve the riddle? Leave your answers in the comment section below.

If you get the correct answer, please share it with your friends and family on WhatsApp, Facebook and other social networking sites.

Answer is 45. Formula is (a x b) + a

13