There are 45 tons of cement in the construction site, (1/5) of the total tonnage is used for the first time, and (1/3) of the total is used for the second time. How many tons are shared twice?
建筑工地有水泥45吨，第一次用去总吨数的(1/5)，第二次用去总数的(1/3)．两次共用去多少吨？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(1/5) + (1/3)</gadget>
<output>8/15 = around 0.533333</output>

<gadget id="calculator">45 * (8/15)</gadget>
<output>24</output>

<result>24</result>