Jerry bought 48 firecrackers for the 4th of July. A police officer discovered and confiscated 12 of them. 1/6 of the remaining ones were defective. If Jerry set off half the good firecrackers, how many firecrackers did he set off?
First subtract the 12 confiscated firecrackers from the original number: 48 firecrackers - 12 firecrackers = 
<gadget id="calculator">48-12</gadget>
<output>36</output>
36 firecrackers.
Then multiply this number by 1/6 to find how many were defective: 36 firecrackers * 1/6 = 
<gadget id="calculator">36*1/6</gadget>
<output>6</output>
6 firecrackers.
Then subtract the defective firecrackers to find how many were good: 36 firecrackers - 6 firecrackers = 
<gadget id="calculator">36-6</gadget>
<output>30</output>
30 firecrackers.
Then divide this number in half to find how many firecrackers Jerry set off: 30 firecrackers / 2 = 
<gadget id="calculator">30/2</gadget>
<output>15</output>
15 firecrackers.

<result>15</result>