There are 10 rectangular pieces of cardboard with a length of 2 cm and a width of 1.5 cm. Use them to form a large rectangular paper. What is the perimeter of this large rectangle in centimeters?
有10张长2厘米、宽1.5厘米的长方形硬纸片，用它们拼成一个大的长方形纸片，这个大长方形的周长是多少厘米．
<gadget id="calculator">10 * 2</gadget>
<output>20</output>

<gadget id="calculator">20 + 1.5</gadget>
<output>21.5</output>

<gadget id="calculator">21.5 * 2</gadget>
<output>43</output>

<result>43</result>