Question

Jana wants to build a pyramid by stacking cups upside down on each other. If the top of the pyramid has 1 cup and the bottom of the pyramid has 6 cups, how many rows of cups are in Jana's pyramid?

Answer 1

Explanation:

Given:

At the top:

1 cup

At the bottom:

6 cups

Using arithmetic progression,

First row, a = 1

Common difference = 1

Final row, an = 6

We are assuming n = number of rows.

Therefore the arithmetic progression, an = ao + (n - 1)d

Inputting values,

6 - 1 = n - 1

n = 6

= 6 rows.

Answer 2

Rows of cups in Jana's pyramid = 7 cups

Explanation:

Rows of cups in Jana's pyramid = 6 + 1 = 7 cups