Ellen decided to play a prank on her friend. She got a case of 12 sodas and shook 3 of them up. Then she took 1 unshaken soda for herself and left. Ellen's brother stopped by and took 1 of the shaken sodas and 2 of the unshaken sodas, then Ellen's friend came along. What is the likelihood, expressed as a percentage, that Ellen's friend gets sprayed with soda from a shaken can?
First figure out how many unshaken sodas were in the case when Ellen left the room: 12 total sodas - 3 shaken sodas - 1 taken soda = 
<gadget id="calculator">12-3-1</gadget>
<output>8</output>
8 unshaken sodas.
Next, figure out how many unshaken sodas were left after Ellen's brother came: 8 - 2 = 
<gadget id="calculator">8-2</gadget>
<output>6</output>
6 unshaken sodas.
Then figure out how many shaken sodas were left after Ellen's brother came: 3 - 1 = 
<gadget id="calculator">3-1</gadget>
<output>2</output>
2 shaken sodas.
Now add the number of shaken and unshaken sodas to find the total number of sodas left when Ellen's friend came along: 2 + 6 = 
<gadget id="calculator">2+6</gadget>
<output>8</output>
8 sodas.
Now divide the number of shaken sodas by the total number of sodas to find the decimal probability Ellen's friend gets sprayed: 2/8 = 
<gadget id="calculator">2/8</gadget>
<output>1/4 = around 0.25</output>
0.25.
Now multiply the decimal probability by 100 to express it as a percentage: .25 * 100 = 
<gadget id="calculator">.25*100</gadget>
<output>25</output>
25%

<result>25</result>