The speed of light is approximately 1,86 * 10^6 miles per second. This approximate speed is how many miles per hour?  Choose the correct choice from the following answers.
A) 1,11 * 10^7	B) 6,70 * 10^7	C) 1,11 * 10^8	D) 6,,70 * 10^9	E) 6,70 * 10^8
The easiest way to answer this question is by POE, it does not require any calculation (answered in 30seconds). In one hour there are 3600 seconds, therefore speed in miles/hour will be.   (1.86*10^6)*3600 = (1.86*10^6)*(3.6*10^3) = some number*10^9..   The key is realizing that thesome numberhas to be bigger thatn 1.86 (because 1.86*3.6), and the only answer that fits that is 6,,70 * 10^9
<result>D</result>
The speed of light is approximately 1,86 * 10^6 miles per second. This approximate speed is how many miles per hour?