The number A is 3.4 times more than the number B. Given that the number A is 20, find the number B.
甲数比乙数的3.4倍多3，已知甲数是20，求乙数．
<gadget id="calculator">20 - 3</gadget>
<output>17</output>

<gadget id="calculator">17 / 3.4</gadget>
<output>5</output>

<result>5</result>