If positive integer x is a multiple of 6 and positive integer y is a multiple of 14,is xy a multiple

题目

If positive integer x is a multiple of 6 and positive integer y is a multiple of 14,is xy a multiple of 105?
(1) x is a multiple of 9.
(2) y is a multiple of 25.
A.Statement (1) ALONE is sufficient,but statement (2) alone is not sufficient.
B.Statement (2) ALONE is sufficient,but statement (1) alone is not sufficient.
C.BOTH statements TOGETHER are sufficient,but NEITHER statement ALONE is sufficient.
D.EACH statement ALONE is sufficient.
E.Statements (1) and (2) TOGETHER are NOT sufficient.
The product of the units digit,the tens digit,and the hundreds digit of the positive integer m is 96.What is the units digit of
(1) m is odd.
(2) The hundreds digit of m is 8.
A.Statement (1) ALONE is sufficient,but statement (2) alone is not sufficient.
B.Statement (2) ALONE is sufficient,but statement (1) alone is not sufficient.
C.BOTH statements TOGETHER are sufficient,but NEITHER statement ALONE is sufficient.
D.EACH statement ALONE is s

答案

x=6a=2*3*a,y=14b=2*7*b,a、b为正整数,x*y=2*2*3*7*a*b105=3*5*7条件(1)并不能保证x*y是105的整数倍,条件(2)可以充分满足x*y是105的整数倍,所以选B设a、b、c为个位数,依题意有：a*b*c=96=2*2*2*2*2*3,m=100a+10b+c,...