In Rodrigo's classroom in the morning there are red chairs, yellow chairs, and blue chairs. There are 4 red chairs. There are 2 times as many yellow chairs as red chairs, and there are 2 fewer blue chairs than yellow chairs. In the afternoon, Lisa borrows 3 chairs.  How many chairs are left in Rodrigo's classroom?
There are 2 * 4 red chairs = 
<gadget id="calculator">2*4</gadget>
<output>8</output>
8 yellow chairs.
There are 8 yellow chairs - 2 = 
<gadget id="calculator">8-2</gadget>
<output>6</output>
6 blue chairs.
Total in the morning there were 4 red + 8 yellow + 6 blue = 
<gadget id="calculator">4+8+6</gadget>
<output>18</output>
18 chairs.
After Lisa removed chairs there were 18 - 3 chairs = 
<gadget id="calculator">18-3</gadget>
<output>15</output>
15 chairs remaining.

<result>15</result>