Question

A pyramid of empty cans has 30 blocks in the bottom row and one fewer can in each successive row therafter. How many cans are there in the pyramid?

Answer 1

Given,

The bottom row of the pyramid has 30 cans.

Each consecutive row has one fewer can.

To find,

Total number of cans in that whole pyramid.

Solution,

We have to keep in mind that, the bottom layer has 30 cans and the top layer has 1 can.

The sequence of the numbers of goes like

= 30,29,28,27.......,2,1

So, we just need to calculate the addition of all thirty numbers in the range of 1 to 30, to get the total number of cans in the pyramid.

To do that, we will use the following mathematical formula,

Sum of 1 to n = {n×(n+1)}/2 = {30×(30+1)}/2 = (30×31)/2 = 465

Hence, there are 465 cans in the pyramid.