Question

What’s the missing number?

Answer 1

7 is the missing number

Explanation:

Let the missing number be x.

Lets study the pattern of the numbers. In each column , we find that the bottom number is the square of the difference of first 2 numbers.

In 1st column ,

Difference of first 2 numbers = 5 - 1 = 4

The bottom number = 16 = 4²

In 2nd column ,

Difference of first 2 numbers = 11 - 4 = 7

The bottom number = 49 = 7²

Similarly ,

Difference of first 2 numbers = 18 - x

The bottom number = 121

`= > {(18 - x)}^(2) = 121`

`= > {(18 - x)}^(2) = {11}^(2)`

`= > 18 - x = 11`

`= > x = 18 - 11 = 7`

Answer 2

Explanation:

Notice that:

1st column = (5 - 1)² = 16

2nd column = (11 - 4)² = 49

Therefore 3rd column = (18 - *)² = 121, * = 7.