There were originally 175 people on the car, 100 people went down on the way, and 30 people came up later, how many people are there in the car now?
车上原有175人，中途下去100人，后来又上来30人，现在车上一共有多少人．
<gadget id="calculator">175 - 100</gadget>
<output>75</output>

<gadget id="calculator">75 + 30</gadget>
<output>105</output>

<result>105</result>