The elder sister is (7/5) meters tall, the younger brother is taller than the older sister (6/7), and the younger sister is taller than the younger brother (5/6). What is the younger sister's height?
姐姐身高(7/5)米，弟弟的身高是姐姐的(6/7)，妹妹的身高是弟弟的(5/6)，妹妹的身高是多少？
<gadget id="calculator">7 / 5</gadget>
<output>7/5 = around 1.4</output>

<gadget id="calculator">6 / 7</gadget>
<output>6/7 = around 0.857143</output>

<gadget id="calculator">5 / 6</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">(7/5) * (6/7) * (5/6)</gadget>
<output>1</output>

<result>1</result>