There is a bucket of boiling water. After filling 8 kettles, there is still (6/7) left. If only 7 kettles are filled, there will be 56 liters left in the bucket. How many liters of water are in each kettle?
有一桶开水，灌满8水壶后，还剩下(6/7)，如果只灌满7水壶，桶里还剩下56升，每个水壶装水多少升？
<gadget id="calculator">6 / 7</gadget>
<output>6/7 = around 0.857143</output>

<gadget id="calculator">1 - (6/7)</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">8 / (1/7)</gadget>
<output>56</output>

<gadget id="calculator">56 - 7</gadget>
<output>49</output>

<gadget id="calculator">56 / 49</gadget>
<output>8/7 = around 1.142857</output>

<result>8/7 = around 1.142857</result>