There is a difference of 15 people between classes A and B. After transferring 1/6 of the number of people in class A to class B, the number of people in the two classes is equal. How many people are there in class B?
甲、乙两班相差15人，把甲班人数的(1/6)调入乙班后，两班人数相等，原来乙班有多少人．
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">15 * (1/6)</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">15 - (5/2) - (5/2)</gadget>
<output>10</output>

<gadget id="calculator">(1/6) - 1</gadget>
<output>-5/6 = around -0.833333</output>

<gadget id="calculator">(1/6) + 1 + (-5/6)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">10 / (1/3)</gadget>
<output>30</output>

<result>30</result>