For any positive integer N, the sum of the first N positive integers equals N(N+1)/2 . If M and N are positive integers and M > N, what is the sum of all the integers between M and N, inclusive? Choose the most appropriate option:
A) M(M+1)/2 + N(N+1)/2	B) M(M+1)/2 - N(N-1)/2	C) M(M+1)/2 - N(N+1)/2	D) M(M+1)/2 + N(N-1)/2	E) M(N+1)/2 - N(M-1)/2
The sum of all the integers between M and N,inclusiveis the sum of the first M positive integersminusthe sum of the first N-1 positive integers.   The sum of the first M positive integers is M(M+1)/2;   The sum of the first N-1 positive integers is (N-1)N/2;   Therefore the answer is M(M+1)/2 - (N-1)N/2.   Answer: M(M+1)/2 - N(N-1)/2.
<result>B</result>
For any positive integer N, the sum of the first N positive integers equals N(N+1)/2 . If M and N are positive integers and M > N, what is the sum of all the integers between M and N, inclusive?