Problem Solving
试题详情
题目：
The sum of the first k positive integers is equal to 
. What is the sum of the integers from n to m, inclusive, where
?
. What is the sum of the integers from n to m, inclusive, where ?选项:
A、
– 
– B、
– 
– C、
– 
– D、
– 
– E、
– 
– 答案:
C
