The ratio of the number of people in the technology group to the composition group is 9:10, and the ratio of the number of people in the composition group to the math group is 5:7. It is known that the mathematics group and the science and technology group have a total of 69 people. How many more people are there in the math group than in the composition group?
科技小组与作文小组的人数比是9：10，作文小组与数学小组人数比是5：7．已知数学小组与科技小组共有69人．数学小组比作文小组多多少人？
<gadget id="calculator">7 / 5</gadget>
<output>7/5 = around 1.4</output>

<gadget id="calculator">(7/5) * 30</gadget>
<output>42</output>

<gadget id="calculator">42 - 30</gadget>
<output>12</output>

<result>12</result>