[求助]GWD10-28

yaskemail

Q28.

For any poitive integer n, the sum of the first n positive integers equals [n(n+1)]/2. What is the sum of all the EVEN integers between 99 and 301?

A. 10,100
B. 20,200
C. 22,650
D. 40,200
E. 45,150

Please help!

hsWang

[(99+301)* 101]/2=20200

选B