A cyclist travels 25 km at 5 km/h and then a further 80 km at 40 km/h. What is his average speed of the journey?

25 km/h

No worries! We‘ve got your back. Try BYJU‘S free classes today!

5 km/h

No worries! We‘ve got your back. Try BYJU‘S free classes today!

20 km/h

No worries! We‘ve got your back. Try BYJU‘S free classes today!

15 km/h

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

Open in App

Solution

The correct option is D
15 km/h

Time taken = $\frac{D i s t a n c e}{S p e e d}$

Ist leg of the journey: Distance = 25 km, Speed = 5 km/h

Time taken to cover the 1st leg of the journey = $\frac{25}{5}$ = 5 hours

2nd leg of the journey: Distance = 80 km, speed = 40 km/h

Time taken to cover the 2nd leg of the journey = $\frac{80}{40}$ = 2 hours

Time taken to cover the entire journey = 5 + 2 = 7 hours

Average speed for the whole journey = $\frac{T o t a l d i s t a n c e t r a v e l l e d}{T o t a l t i m e t a k e n}$

= $\frac{25 + 80}{7}$ = $\frac{105}{7}$ = 15 km/h

Suggest Corrections

Similar questions

Q. A

100 m

long train crosses a man travelling at

5 km/h

, in opposite direction, in

7.2 s

. Then the velocity of the train is

Q. A car travels from

A

B

at a speed of

20 km/h

and returns at a speed of

30 km/h

. The average speed of the car for the whole journey is

A train travels 360 km at a uniform speed. If the speed had been 5 km/h more, it would have taken 1 hour less for the same journey. Find the speed of the train.

Q. The minimum speed of wind necessary for the satisfactory working of a wind generator to produce electricity is about:

(a) 15 km/h
(b) 25 km/h
(c) 35 km/h
(d) 45 km/h

Q. Joe enters a race where he has to cycle and run, he cycles a distance of

25

Km, and then runs for

20

Km. His average running speed is half of his average cycling speed.
Joe completes the race in less than

2.5

hrs, then the average speed of Joe throughout the race is

Join BYJU'S Learning Program