If x and y are integers, what is the least positive number of 24x+21y?	Pick one.
A) 3 B) 5 C) 6 D) 8 E) 9
24x+21y = 3(8x+7y) which will be a minimum positive number when 8x+7y = 1.   8(1) + 7(-1) = 1   Then 3(8x+7y) can have a minimum positive value of 3.   The answer is 3.
<result>A</result>
If x and y are integers, what is the least positive number of 24x+21y?