204 If x is equal to the sum of the even integers from 40 to 60, inclusive, and y is the number of even integers from 40 to 60, inclusive, what is the value of x + y ? A 550 B 551 C 560 D 561 E 572 答案D OG將求出來的11個偶數用數字總和公式加起來--> x=11(40+60)/2=550 但是這個數字和公式是算總和的 這樣也把奇數(41、43...)算進去了呀 想請問牛牛 我的思路哪裡錯了呢 ? 感激在心
