During a trip, Francine traveled x percent of the total distance at an average speed of 60 miles per hour and the rest of the distance at an average speed of 40 miles per hour. In terms of x, what was Francineâ€™s average speed for the entire trip?  Choose the correct answer
A) (180-x)/2 B) (x+60)/4 C) (300-x)/5 D) 12,000/(300-x) E) 12,000/(x+200)
D....   X% traveeled at 60 mph   100-X% traveeled at 40 mph   total timt taken = x/60 +(100-x)/40 = (300-x)/120   Total distance = x+(100-x) = 100   Av speed = Tot 12,000/(300-x)is/Time Taken which is 12,000/(300-x)
<result>D</result>
During a trip, Francine traveled x percent of the total distance at an average speed of 60 miles per hour and the rest of the distance at an average speed of 40 miles per hour. In terms of x, what was Francineâ€™s average speed for the entire trip?