The number A is 15, which is 3 times less than the number B, what is the number B
甲数是15，比乙数的3倍少3，乙数是多少
<gadget id="calculator">15 + 3</gadget>
<output>18</output>

<gadget id="calculator">18 / 3</gadget>
<output>6</output>

<result>6</result>