Question

寧兒吖～

請教這題🙏

17. 若正整數n的所有正因數,由小到大排列依序為1,a,b,c,d,e
10,f,g,h,i,35,42,j,k,n,則c+d+h的值為何?
(A) 32
(B) 34
(C) 42
(D) 44

Answer 1

Ny-Ålesund

質因數分解後，頭尾相乘等於原本的數字
例如：
12 = 1 * 12 = 2 * 6 = 3 * 4
依序排列 1, 2, 3, 4, 6, 12，頭尾相乘等於原本的數字
所以
1n = ak = bj = 42c = 35d = ei = 10h = fg

42c = 35d = 10h 找最小公倍數
[42, 35, 10] = 210
--> c = 5, d = 6, h = 21

寧兒吖～

這題會了，謝謝🙏

Ny-Ålesund

忘記附圖