There are 3 classes in grade six, the number of students in class one accounts for 25% of the total number of students in the three classes, the ratio of the number of students in class two to class three is 7:8, and the number of students in class one is 24 less than that in class three. How many students are there in the sixth grade?
六年级有3个班，一班人数占三个班总人数的25%，二班和三班人数比是7：8，一班比三班人数少24人．六年级共有学生多少人．
<gadget id="calculator">7 + 8</gadget>
<output>15</output>

<gadget id="calculator">8 / 15</gadget>
<output>8/15 = around 0.533333</output>

<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/4)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">(8/15) * (3/4)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(2/5) - (1/4)</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">24 / (3/20)</gadget>
<output>160</output>

<result>160</result>