[問題]GWD0-36

[colorr]

If M is the least common multiple of 90, 196, and 300, which of the following is NOT a factor of M?

A. 600

B. 700

C. 900

D. 2,100

E. 4,900

答案是A
我怎麼覺得每個答案都對 dora25

[agk99]

90=2*3*3*5
196=2*2*7*7
300=2*2*3*5*5
所以最小公倍數=(2*3*5*7)的二次方

你把五個數分別代入，你就發現600=2*3*(2*5)^2
等於是2連乘了3次，當然不合標準
這一題要實際做，用看的不太容易看出來

[colorr]

終於懂了，感謝感謝