car travels a total of 300 km for 4 hours in the morning, and travels at the same speed for 3 hours in the afternoon. How many kilometers did the car travel in a day? (Use proportions to solve.)
一辆汽车上午行了4小时共行300km，下午又以同样的速度行了3小时．该汽车一天共行了多少千米？(用比例解．)
<gadget id="calculator">300 / 4</gadget>
<output>75</output>

<gadget id="calculator">75 * 3</gadget>
<output>225</output>

<gadget id="calculator">75 * 4</gadget>
<output>300</output>

<gadget id="calculator">225 + 300</gadget>
<output>525</output>

<result>525</result>