Kindergarten teachers distribute 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?
幼儿园老师把购进饼干的按3：2分配给大班和中班．已知大班分得12千克．幼儿园老师一共购进多少千克饼干？
<gadget id="calculator">3 + 2</gadget>
<output>5</output>

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

<gadget id="calculator">12 / (3/5)</gadget>
<output>20</output>

<result>20</result>