A factory uses 3.5 tons of coal in the first month, which is 1/5 more tons than in the second month. How many tons of coal are used in the two months?
某工厂第一个月用煤3.5吨，比第二个月多(1/5)吨，两个月共用煤多少吨？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">3.5 - (1/5)</gadget>
<output>3.3</output>

<gadget id="calculator">3.3 + 3.5</gadget>
<output>6.8</output>

<result>6.8</result>