There is a pile of sand on the construction site in the shape of a cone. Its bottom surface is 31.4 meters in circumference and 60 decimeters in height. Each cubic meter of sand weighs about 1.6 tons. How many tons is this pile of sand in total?
建筑工地有一堆沙子呈圆锥形，它的底面周长31.4米，高60分米，每立方米沙子重约1.6吨，这堆沙子共多少吨？
<gadget id="calculator">78.6 * 2</gadget>
<output>157.2</output>

<gadget id="calculator">1.6 * 157.2</gadget>
<output>251.52</output>

<result>251.52</result>