The school cafeteria originally had (3/4) tons of rice, but (2/5) tons were eaten in the first 3 days, and the remaining 2 days were eaten. How many tons are eaten on average per day?
学校食堂原有(3/4)吨大米，前3天吃掉(2/5)吨，剩下的2天吃完，剩下的平均每天吃多少吨？
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(3/4) - (2/5)</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">(7/20) / 2</gadget>
<output>7/40 = around 0.175</output>

<result>7/40 = around 0.175</result>