There are 280 cows on the farm, the number of pigs is 3/4 of that of cows, and 70% of that of sheep. How many sheep are there on the farm?
农场有牛280头，猪的头数是牛的(3/4)，又是羊的70%，农场养羊多少只．
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">70 / 100</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">(3/4) / (7/10)</gadget>
<output>15/14 = around 1.071429</output>

<gadget id="calculator">280 * (15/14)</gadget>
<output>300</output>

<result>300</result>