(1/3) people got off the No. 16 bus at Shuimen Bridge, and 20 people got on the bus. The number of people on the bus here is more than before (1/7). How many people were on the bus?
16路公交车在水门桥有(1/3)的人下车，又有20人上车，这里车上的人比原来多(1/7)，原来车上有多少人？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">(1/3) + (1/7)</gadget>
<output>10/21 = around 0.47619</output>

<gadget id="calculator">20 / (10/21)</gadget>
<output>42</output>

<result>42</result>