The weight ratio of the three piles of coal A, B, and C is 2:3:5. The three piles of coal weigh 15 tons in total. How many tons is A less than B?
甲、乙、丙三堆煤的重量比是2：3：5，三堆煤共重15吨，甲比乙少多少吨？
<gadget id="calculator">2 + 3 + 5</gadget>
<output>10</output>

<gadget id="calculator">2 / 10</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/5) / 10</gadget>
<output>1/50 = around 0.02</output>

<gadget id="calculator">15 * (1/50)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(3/10) - (1/5)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">15 * (1/10)</gadget>
<output>3/2 = around 1.5</output>

<result>3/2 = around 1.5</result>