The number A is (1/7) of the number B, the number B is (2/15) of the number C, and the number A is equal to 20. What is the propane number?
甲数是乙数的(1/7)，乙数是丙数的(2/15)，甲数等于20．丙数是多少？
<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">2 / 15</gadget>
<output>2/15 = around 0.133333</output>

<gadget id="calculator">20 / (1/7) / (2/15)</gadget>
<output>1_050</output>

<result>1_050</result>