Samantha takes 3 hours to travel from place X to place Y at a speed of 75 miles per hour. She takes 2 hours to travel from place Y to Z with 30% increased speed. Find her average speed during the entire journey.
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 84 miles per hour
Speed of Samantha while covering XY = 75 miles/h
Total distance between X and Y = 75 × 3 = 225 miles
Speed of Samantha while covering YZ = 75 × 130/100 = 97.5 miles/h
Total distance between Y and Z = 97.5 × 2 = 195 miles
Average Speed = Total distance/Total time = {225 + 195}/{2+3} = 420/5 = 84 miles/h