The first three towers in a sequence are shown. The nth tower is formed by stacking n blocks on top of an n times n square of blocks. How many blocks are in the 99th tower?

The 99th tower contains 9900 blocks.

Step-by-step explanation:

From the question given, we were told that the nth tower is formed by stacking n blocks on top of an n times n square of blocks. This implies that the number of blocks in n tower will be:

n + n²

Now let us use the diagram to validate the idea.

Tower 1:

n = 1

Number of blocks = 1 + 1² = 2

Tower 2:

Number of blocks = 2 + 2² = 6

Tower 3:

Number of blocks = 3 + 3² = 12

Using same idea, we can obtain the number of blocks in the 99th tower as follow:

Tower 99:

n = 99

Number of blocks = 99 + 99² = 9900

Therefore, the 99th tower contains 9900 blocks.