A man travels first $50 k m$ at $25 k m p h$ , next $40 k m$ at $20 k m p h$ and then $90 k m$ at $15 k m p h$ . His average speed for the whole journey $(i n k m p h)$ is:

25

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

20

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

18

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

40

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

Open in App

Solution

The correct option is C $18$
To find : average speed
$s p e e d = \frac{D i s t a n c e}{T i m e}$
$ϑ_{1} = \frac{s_{1}}{t_{1}} \Rightarrow t_{1} = \frac{s_{1}}{ϑ_{1}}$
$t_{1} = \frac{50}{25} = 2$ hrs
$t_{2} = \frac{s_{2}}{ϑ_{2}} = \frac{40}{20} = 2$ hrs
$t_{3} = \frac{s_{3}}{ϑ_{3}} = \frac{90}{15} = 6$ hrs
Average Speed $\frac{T o t a l D i s t a n c e}{T o t a l t i m e t a k e n}$
$= \frac{s_{1} + s_{2} + s_{3}}{t_{1} + t_{2} + t_{3}} = \frac{50 + 40 + 90}{2 + 2 + 6}$ km/h
$= \frac{180}{10}$ km/h
= 18 km/h

Suggest Corrections

Similar questions

Q. A man travels

1^{s t}

50 km at 25 km/hr next 40 km with 20 km/hr and then 90 km at 15 km/hr Then find his average speed for the whole journey (in km/hr)

On a 200 km track,a train travelles first 50 km at a uniform speed of 40 km/h. How fast should it travel the next 150 km to maintain an average speed of 60 km/h for the whole journey

Q. A man travels the first part of his journey at 20 km/h and the next at 70 km/h, covering the entire journey at an average speed of 50 km/h. What is the ratio of the distace that he covered at 20 km/h to that he covered at 70 km/h?

The distance between Delhi and Agra is 200km .A train travels the first 100km at a speed of 50km/h .How fast must the train travel the next 100km ,so as to average 70km/h for the whole journey?

A train travels the first 15 km at a uniform speed of 30 km/h; the next 75 km at a uniform speed of 50 km/h; and the last 10 km at a uniform speed of 20 km/h. Calculate the average speed for the entire train journey.

A man travels first 50 km at 25 kmph, next 40 km at 20 kmph and then 90 km at 15 kmph. His average speed for the whole journey (in kmph) is:

The correct option is C 18To find : average speedspeed=DistanceTimeϑ1=s1t1⇒t1=s1ϑ1t1=5025=2 hrst2=s2ϑ2=4020=2 hrst3=s3ϑ3=9015=6 hrsAverage Speed TotalDistanceTotaltimetaken=s1+s2+s3t1+t2+t3=50+40+902+2+6 km/h=18010 km/h = 18 km/h

A man travels first $50 k m$ at $25 k m p h$ , next $40 k m$ at $20 k m p h$ and then $90 k m$ at $15 k m p h$ . His average speed for the whole journey $(i n k m p h)$ is: