A barrel of oil weighs 40 tons, and (1/8) is used for the first time, and (3/5) is used for the second time, how many kilograms are used for the two times?
一桶油重40吨，第一次用去了(1/8)，第二次用去(3/5)，两次一共用去多少千克？
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(1/8) + (3/5)</gadget>
<output>29/40 = around 0.725</output>

<gadget id="calculator">40 * (29/40)</gadget>
<output>29</output>

<result>29</result>