2,4,6,....2k is the series of items where n=2k+1arjunsekhar wrote:1. The sum of the even numbers between 1 and n is 79*80, where n is an odd number, then n=?
2(1+2+3+...k)
=2(k(k+1))/2
=k(k+1) = 79*80
Hence k should be 79
Hence n= 2(79) +1 = 159
Hope this helps!!
