If you take the fastest speed of a rabbit and double it, add 4 to that then double it again you get 188.  How fast is the rabbit?
You doubled a number to get 188 so in reverse, you would divide by 2 so 188/2 = 
<gadget id="calculator">188/2</gadget>
<output>94</output>
94.
You added 4 to this number and in reverse, you would subtract by 4 so 94-4= 
<gadget id="calculator">94-4</gadget>
<output>90</output>
90.
You doubled a number to get 90 so in reverse you would divide by 2 so 90/2 = 
<gadget id="calculator">90/2</gadget>
<output>45</output>
45 is the fastest speed.

<result>45</result>