Q. While in San Francisco some time back, I hired a car to drive over the Golden Gate bridge. 1 started in the ; fternoon when there was no traffic rush. So I could do 40 miles an hour. While returning, however, I got caught in the traffic rush and I could only manage to drive at a speed of 25 miles an hour. What was my average speed for the round trip?

• The formula for average speed, when the distance covered is the same is
  2(a)(b)/2ab here a is the speed of the "to" journey and b is the speed of the " fro" journey.
  Applying the same formula, the answer will be (2)(25)(40)/(25+40) = 2000/65 = 400/13 = 30 10/13 miles an hour (or) 30.769 miles an hour
• 11 years agoHelpfull: Yes(6) No(0)