It is known that A=2*3*3*a, B=2*2*3*a, and the greatest common factor of A and B is 30, then a=how much.
已知A=2*3*3*a，B=2*2*3*a，且A、B的最大公因数是30，则a=多少．
<gadget id="calculator">30 / 6</gadget>
<output>5</output>

<result>5</result>