A car traveled 80% of the way from Town X to Town Y at an average speed of 80 mph. The car traveled at an average speed of v mph for the remaining part of the trip. The average speed for the entire trip was 50 mph. What is v in mph? Select the correct option
A) 25
B) 35
C) 45
D) 55
E) 20

Rationale: assume total distance = 100 miles time taken for 80 miles = 80 / 80 = 1 hour time taken for the rest of the 20 miles = 20 / v hours . average speed = 50 therefore the total time needed = 2 hours . 2 = 1 + 20 / v hence v = 20 mph answer : e
Answer: E