How do you calculate the number of cans in this arithmetic progression?
Cans are arranged in a pile such that each row has one less can than the row below. There is a total of 3240 cans in the pile. How many cans are there in the bottom row?
Cans are arranged in a pile such that each row has one less can than the row below. There is a total of 3240 cans in the pile. How many cans are there in the bottom row?
1 Answer
Jan 5, 2018
Explanation:
If there is one can in the top row and there are
1/2 n (n+1)
So let's try to solve:
3240 = 1/2 n(n+1)
Multiply both sides by
6480 = n(n+1)
Note that
So there are