Question

if you drive from banglore to chennie at 40kmph and then from chennie to banglore 60kmph what is your speed for whole journey explanation video
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Answer 1

Answer:

avg speed = (40 + 60 ) / 2

avg speed = 100/2 = 50 kmph

Answer 2

ANSWER:

Given:

Speed taken to Drive from Bangalore to Chennai - 40kmph

Speed taken to Drive back from Chennai to Bangalore - 60kmph

To Find:

The Speed taken for the Whole Journey [Average Speed]

Solution:

Let us Suppose that the Distance from Bangalore to Chennai be x km.

On their way to Chennai, their Given Speed is 40kmph and The Time Taken to reach Chennai be $t_{1}$

By the Formula, $Speed = \frac{Distance\:Travelled}{Time\:Taken}$,

$:=>40kmph=\frac{x}{t_{1}} \\\\Therefore, Time\:Taken(t_{1}) = \frac{x}{40} hrs$

On their Return to Bangalore, their Given Speed is 60kmph & The Time Taken for Returning to Bangalore be $t_{2}$

By the Same Formula of Speed given above,

$:=>60kmph=\frac{x}{t_{2}} \\\\Thererfore, Time\:Taken (t_{2}) = \frac{x}{60} hrs$

Now, Consider the Whole Journey, i.e., Going to Chennai & back to Bangalore,

Total Distance = 2x [x + x]

Total Time Taken = $\frac{x}{40} +\frac{x}{60} \\\\LCM\:of 40\:and\:60 \:is = 120\\\\ \frac{x}{40}*3+\frac{x}{60} *2=\frac{3x+2x}{120} =\frac{5x}{120} =\frac{x}{24} hrs$

Using the Formula of Average Speed = $\frac{Total\:Diatance\:Travelled}{Total\:Time\:Taken}$

$2x/\frac{x}{24} =\frac{(2x)(24)}{x} =2*24 = 48kmph$

CONCLUSION:

The Average Speed of the Whole Journey is 48kmph