Lin creates a pattern using the white and black tiles.

The number of white tiles present in the next shape of Lin’s pattern is _____.

The correct answer is: 16

The number of tiles is increasing with the number of shape. 
The rule used to create the shape is the number of tiles is given by a square. And the number is increasing by 1.
The first shape requires 1² = 1 white tiles.
The second shape requires 2² = 4 white tiles.
The third shape requires 3² = 9 white tiles.
So, the next figure will be square of next number that is 4.
Therefore, 4^th shape requires 4² = 16 white tiles.

We have to be careful about the sequence of the shape. We have to increase the number of tiles in proper order.