Number A=2*3*7*a; Number B=2*3*5*b; when a=how much, the greatest common divisor of the two numbers of A and B is 30.
甲数=2*3*7*a；乙数=2*3*5*b；当a=多少时，甲乙两数的最大公约数是30．
<gadget id="calculator">30 / 2 / 3</gadget>
<output>5</output>

<result>5</result>