精華區beta GMAT 關於我們 聯絡資訊
7. For every positive even integer n, the function h(n) is defined to be the product of all the even integers from 2 to n, inclusive. If p is the smallest prime factor of h(100) + 1, then p is (A) between 2 and 10 (B) between 10 and 20 (C) between 20 and 30 (D) between 30 and 40 (E) greater than 40 這題解法由(2*4*6*8...*100)+1=2^50*50!+1 解起 我想問的是為什麼(2*4*6*8...*100)+1 會等於 2^50*50!+1 ? -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 163.13.36.176
tgbh:(2*4*6*8...*100)+1 = 2[1*2*3*4....*50]+1 07/23 11:51
william1001:所以是 2*50!+1而不是 2^50*50!+1 ? 07/23 12:35
DanceDan:2要提五十次出來~所以是2^50 07/23 20:19
DanceDan:請問接下來怎麼解啊? 07/23 20:19