During a trip, Francine traveled x percent of the total distance at an average speed of 30 miles per hour and the rest of the distance at an average speed of 70 miles per hour. In terms of x, what was Francineâ€™s average speed for the entire trip? Choose the most appropriate option.
A) (180-x)/2 B) (x+60)/4 C) 21,000/(300+4x) D) 600/(115-x) E) 12,000/(x+200)
E....   X% traveeled at 30 mph   100-X% traveeled at 70 mph   total timt taken = x/30 +(100-x)/70 = (300+4x)/210   Total distance = x+(100-x) = 100   Av speed = Tot Dis/Time Taken which is 21,000/(300+4x)
<result>C</result>
During a trip, Francine traveled x percent of the total distance at an average speed of 30 miles per hour and the rest of the distance at an average speed of 70 miles per hour. In terms of x, what was Francineâ€™s average speed for the entire trip?