A group photo of 18 members of a school volleyball team costs 13 yuan and 50 cents for taking a 6-inch photo and developing 3 photos. Additional laundering costs 30 cents for each piece. If each person gets one piece, how much is the average cost per person.
某校排球队18人合影留念，照6寸照片洗3张照片，需13元5角．要另外加洗，每张3角，如果每人各得一张，平均每人需交多少元钱．
<gadget id="calculator">18 - 3</gadget>
<output>15</output>

<gadget id="calculator">15 * 3</gadget>
<output>45</output>

<gadget id="calculator">135 + 45</gadget>
<output>180</output>

<gadget id="calculator">180 / 10</gadget>
<output>18</output>

<gadget id="calculator">18 / 18</gadget>
<output>1</output>

<result>1</result>