The average of the two numbers of A and B is 75, the ratio of A and B is 8:7, how much is the difference between the two numbers of A and B?
甲乙两数的平均数是75，甲数与乙数的比是8：7，甲乙两数相差多少．
<gadget id="calculator">8 + 7</gadget>
<output>15</output>

<gadget id="calculator">2 / 15</gadget>
<output>2/15 = around 0.133333</output>

<gadget id="calculator">8 - 7</gadget>
<output>1</output>

<gadget id="calculator">75 * (2/15) * 1</gadget>
<output>10</output>

<result>10</result>