AI Mentor

Check Your IQ

Free Expert Demo

Try Test

Courses

Dropper NEET Course Dropper JEE Course Class - 12 NEET Course Class - 12 JEE Course Class - 11 NEET Course Class - 11 JEE Course Class - 10 Foundation NEET Course Class - 10 Foundation JEE Course Class - 10 CBSE Course Class - 9 Foundation NEET Course Class - 9 Foundation JEE Course Class -9 CBSE Course Class - 8 CBSE Course Class - 7 CBSE Course Class - 6 CBSE Course

Offline Centres

A car travels from city A to city B, $120 km$ apart at an average speed of $50 kmph$ . It then makes a return trip at an average speed of $60 kmph$ . It covers another $120 km$ distance at an average speed of $40 kmph$ . The average speed over the entire $360 km$ will be

see full answer

Your Exam Success, Personally Taken Care Of

1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.

An Intiative by Sri Chaitanya

60kmph

30kmph

50.5kmph

48.64kmph

answer is D.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

NEET

Foundation JEE

Foundation NEET

CBSE

Detailed Solution

It is given that, a car travels from city A to city B.
The two cities are 120km apart. Average speed of car is

50 km / hr

.
It then makes a return trip at an average speed of

60 km / hr .

It covers another 120km distance at an average speed of

40 km / hr

.
The speed of the object is the ratio of the distance traveled by the object over the time taken.
Thus, the time taken from city A to city B is,

t 1 = 12050 kmph

The time taken in return trip is,

t 2 = 12060 kmph

And, the time taken in covering another distance is,

t 3 = 12040 kmph

Total distance d is 360km.
Therefore, the average speed is,

S = d t 1 + t 2 + t 3 ⇒ S = 360 12050 + 12060 + 2040 ⇒ S = 360 7.4 ⇒ S = 48.64 kmph

Thus, the average speed is 48.64kmph.
Therefore, option (4) is correct.

Watch 3-min video & get full concept clarity

courses

No courses found

Result Producing online coaching for JEE/NEET of south India

Largest All India Test Series for JEE/NEET

Best Online Course for IIT JEE

Best Online Course for NEET

Best Online Course for CBSE

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Get Expert Academic Guidance – Connect with a Counselor Today!