The sum of the first $N$ positive odd numbers is 121. What is the value of $N$?
Note that the sum of the first four odd positive integers = 1 + 3 + 5 + 7 = 16 = 4^2
So....the sum of the first N positive odd integers = N^2
So
N^2 =121 take the square root
N = 11
thanks i didn't know about the sum of the consecutive odd numbers were squared.
