Use app×
JEE MAIN 2024
JEE MAIN 2025 Foundation Course
NEET 2024 Crash Course
NEET 2025 Foundation Course
CLASS 12 FOUNDATION COURSE
CLASS 10 FOUNDATION COURSE
CLASS 9 FOUNDATION COURSE
CLASS 8 FOUNDATION COURSE
0 votes
327 views
in Mathematics by (40.8k points)
closed by
A train travels between two stations A and B . While going from A to B, its average speed is 80 km/hr, and when coming back from B to A . Its average speed is 120km/hr. find the average speed of the train during the whole journey.

1 Answer

0 votes
by (43.4k points)
selected by
 
Best answer
Let the distance between A and B be x km.
Average speed while going from A to B = 80 km/hr.
Time taken to cover x km from A to B = `(x/80)` hours.
Average speed while coming from B to A =120 km/hr.
Time taken to cover x km from B toA = `( x/120)` hours.
Total time taken to cover 2x km = `( x/80 +x/120) " hours " = (x/48)` hours.
Average speed during the whole journey
` "distance"/"time" = (2x)/((x //48)) km //hr = 96` km/hr ltbr. Hence the average speed of the trian during the whole journey is 96 km/hr.

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.

Categories

...