The ratio of the number of boys to girls in Class 61 is 5:4. There are 4 more boys than girls. How many people are there in Class 61?
六一班男生与女生人数的之比是5：4，男生比女生多4人，六一班一共有多少人．
<gadget id="calculator">5 - 4</gadget>
<output>1</output>

<gadget id="calculator">4 / 1</gadget>
<output>4</output>

<gadget id="calculator">5 + 4</gadget>
<output>9</output>

<gadget id="calculator">4 * 9</gadget>
<output>36</output>

<result>36</result>