PS Form-24 sec3-Q20

[addway]

An integer n that is greater than 1 is said to be "prime-saturated" if it has no prime factor greater than or equal to √n. Which of the following integers is prime-saturated

(A) 6 (B) 35 (C) 46 (D) 66 (E) 75

Ans: E


請高人幫幫忙
感恩啦

[scujean]

[解]題目要求"prime-saturated"須符合 選項中的質因子不能 大于等於[根號n]
一各一個代
6=2*3
根號6=2.多 那麼3這個質數大於2.多 此項不符
35=5*7
根號35=5.多 那7這個質數大於5.多
最後75=3*5*5
根號75=8.多 3或5都小於 8.多

[addway]

it is so clear
I get it
thanks a lot