The greatest common divisor of two numbers A and B is 3, and the least common multiple is 30. It is known that the number A is 6, and what is the number B.
甲、乙两数的最大公约数是3，最小公倍数是30，已知甲数是6，乙数是多少．
<gadget id="calculator">30 / 6</gadget>
<output>5</output>

<gadget id="calculator">3 * 5</gadget>
<output>15</output>

<result>15</result>