The greatest common factor of two numbers A and B is 20, and the least common multiple is 420. If the number A is 60, what is the number B?
甲、乙两数的最大公因数是20，最小公倍数是420，如果甲数是60，乙数是多少．
<gadget id="calculator">2 * 2 * 5 * 7</gadget>
<output>140</output>

<result>140</result>