The photo studio takes photos of a certain specification, and the price is 5.40 yuan for 3 pieces, and 0.40 yuan for each photo if additional printing is required. There are 20 people in class 505 taking a group photo, and each person needs one. How much does each person pay on average.
照相馆照某种规格的像片，价格为3张5.40元，如果需要加印，每张0.40元．505班有20人合影留念，每人要1张．平均每人应付多少元．
<gadget id="calculator">20 - 3</gadget>
<output>17</output>

<gadget id="calculator">0.4 * 17</gadget>
<output>6.8</output>

<gadget id="calculator">5.4 + 6.8</gadget>
<output>12.2</output>

<gadget id="calculator">12.2 / 20</gadget>
<output>0.61</output>

<result>0.61</result>