Frederique traveled x/8 of the total distance of a trip at an average speed of 40 miles per hour, where 1=<x=<7. She traveled the rest of the distance at an average speed of 60 miles per hour. In terms of x, what was Frederique's average speed for the entire trip?  Choose one:	A) (180-x)/2	B) (x+60)/4	C) (300-x)/8	D) 800/(120+x)	E) 960/(x+16
Let total distance is 200 miles and X=4.   So, half(4/8) of the distance i.e. 100 miles was traveled at 40 mph and rest 100 at 60 mph.   Thus, the average speed will be (2*40*60)/(40+60)= 
<gadget id="calculator">(2*40*60)/(40+60)</gadget>
<output>48</output>
48.   Now plugging in the value of x in the answer choices, we get 960/(x+16 as 48.
<result>E</result>
Frederique traveled x/8 of the total distance of a trip at an average speed of 40 miles per hour, where 1=<x=<7. She traveled the rest of the distance at an average speed of 60 miles per hour. In terms of x, what was Frederique's average speed for the entire trip?