Question

If 2 = 6, 3 =12, 4 = 20, 5 = 30, 6 = 42 then 9 = ?

Answer 1

At first you may get confused but look at those numbers carefully :)

as you see first result is divisible buy one of the product (second product in all cases is unknown)
so let's check where it will lead us :)


`6/2=3`


`12/3=4`


`20/4=5`


`30/5=6`


`42/6=7`

Now you can clearly see that every number was multiplied by number 1 higher than itself.

`2*(2+1)=6`


`3*(3+1)=12`


`4*(4+1)=20`

etc...

it means that after equation sign there should be
`90` because


`9*(9+1)=90` :)