求解题思路 （OG12 PROBLEM SOLVING 85）

happywulicy

In an increasing sequence of 10 consecutive integers,
the sum of the first 5 integers is 560. What is the sum
of the last 5 integers in the sequence?
(A) 585
(B) 580
(C) 575
(D) 570
(E) 565

happywulicy

答案是A我算的结果是B, 不知谁错了