With the money on Mr. Wang, if you buy 3 items of Type A, you will still be short of 6 yuan; if you buy 4 items of Type B, you will still be short of 30 yuan. It is known that the unit price of commodity B is (7/8) that of commodity A. How much is the unit price of commodity A?
王老师身上的钱，如果买3件甲种商品还缺6元；如果买4件乙种商品还缺30元．已知乙种商品的单价是甲种商品的(7/8)，问甲种商品的单价是多少元？
<gadget id="calculator">30 - 6</gadget>
<output>24</output>

<gadget id="calculator">7 / 8</gadget>
<output>7/8 = around 0.875</output>

<gadget id="calculator">4 * (7/8)</gadget>
<output>7/2 = around 3.5</output>

<gadget id="calculator">(7/2) - 3</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">24 / (1/2)</gadget>
<output>48</output>

<result>48</result>