The sand on the construction site is 6 tons more than the cement. After two days of use, the quality of the sand and cement is equal. It is known that there is still (2/7) of sand left and 8 tons of cement left. How many tons of original sand are there?
工地上的沙子比水泥多6吨，用了两天后，沙子与水泥的质量相等．已知沙子还剩(2/7)，水泥还剩8吨，原有沙子多少吨．
<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">8 / (2/7)</gadget>
<output>28</output>

<result>28</result>