A bus departs from the departure station with one passenger per seat and no standing passengers. At the first stop, passengers went down (1/7), and 16 people came up; at the second stop, passengers went down (1/5) of the total number, and 5 people came up again, and the seats were full at this time Passengers, and another 9 passengers stand to watch. How many seats are there in the car?
一辆公共汽车从始发站出发，车上每个座位上坐着一位乘客，且没有站着的乘客．到第一站，乘客下去了(1/7)，又上来了16人；到第二站，乘客下去了总人数的(1/5)，又上来了5人，这时座位上都坐满了乘客，另外还有9位乘客站看．车上有多少个座位？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">16 * (1/5)</gadget>
<output>16/5 = around 3.2</output>

<gadget id="calculator">5 - (16/5) - 9</gadget>
<output>-36/5 = around -7.2</output>

<gadget id="calculator">16 + (-36/5)</gadget>
<output>44/5 = around 8.8</output>

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

<gadget id="calculator">(1/7) * (1/5)</gadget>
<output>1/35 = around 0.028571</output>

<gadget id="calculator">1 - 1 - (1/35)</gadget>
<output>-1/35 = around -0.028571</output>

<gadget id="calculator">(1/5) + (1/7) + (-1/35)</gadget>
<output>11/35 = around 0.314286</output>

<gadget id="calculator">(44/5) / (11/35)</gadget>
<output>28</output>

<result>28</result>