Kindergarten teachers allocate (2/5) the purchase of biscuits to the big class and the middle class at a ratio of 3:2. It is known that the big class is divided into 12 kilograms. How many kilograms of biscuits did the kindergarten teacher buy in total?
幼儿园老师把进购饼干的(2/5)按3：2分配给大班和中班．已知大班分得12千克．幼儿园老师一共进购多少千克饼干？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">12 / (2/5)</gadget>
<output>30</output>

<gadget id="calculator">2 + 3</gadget>
<output>5</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">30 * (3/5)</gadget>
<output>18</output>

<result>18</result>