The number A is 99, which is 15 more than three times the number B, what is the number B
甲数是99，比乙数的3倍多15，乙数是多少
<gadget id="calculator">99 - 15</gadget>
<output>84</output>

<gadget id="calculator">84 / 3</gadget>
<output>28</output>

<result>28</result>