Is the integer k divisible by 4 ?
(1) 8k is divisible by 16.
(2) 9k is divisible by 12.
Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
EACH statement ALONE is sufficient.
Statements (1) and (2) TOGETHER are NOT sufficient.
条件1只能说明K可以被2整除无法说明可以被4整除。条件2化简得3k/4-----k/4可以被整除
条件2化简得到3k是4的倍数,因为3k的3是质数,不包含4,所以3k如果要是4的倍数,K一定是4的倍数。
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3K 可以被4整除,3 和4互斥,所以k一定能被4整除
k是整数
(1) 8k is divisible by 16. 即8*k能被8*2整除,k能被2整除
(2) 9k is divisible by 12. 即3*3k能被3*4整除,3k能被4整除,k能被4整除
条件一,K可以被2整除;
条件二,3K 可以被4整除,3 和4互斥,所有K里面肯定有4.
把条件一化简得出k is divisible by 2,不成立,因为k可以被2整除,不能代表k能够被4整除;把条件二化简得出3k is divisible by 4,我们现在把原条件k/4 上下同乘以3得出 3k/12,所以根据条件二得出,3k可以被4整除,那证明k肯定有一个约数是4,所以3k可以整除12.