Number A=2*3*7*A, Number B=2*5*7*A, when A=how many, the greatest common divisor of A and B is 42.
甲数=2*3*7*A，乙数=2*5*7*A，当A=多少时，甲、乙两数的最大公约数是42．
<gadget id="calculator">42 / 2 / 7</gadget>
<output>3</output>

<result>3</result>