The selling price of a commodity after a 20% discount is 120 yuan, how much is the selling price after a 30% discount.
一种商品八折优惠后的售价是120元，七折优惠后的售价是多少元．
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">120 / (4/5)</gadget>
<output>150</output>

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

<gadget id="calculator">150 * (7/10)</gadget>
<output>105</output>

<result>105</result>