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jackenergy

If K is common multiple of 75, 98, 140, which of the following must be true?
!. K is a multiple of 9
II. K is a multiple of 49
III. K is greater than 14000

这题的答案究竟是那个，请指教details

joywzy

ans : II,III

75=3*5^2
98=2*7^2
140=7*5*2^2
so K=2^2*3*5^2*7^2
so ,II and III

jackenergy

Thanks a lot!