Atrain goes from new orleans to boston at 40 mph. on the way back it returns with a speed 80 mph. if it takes it an hour less time to return, what is its average speed?

Speed is the ratio of distance and time.

So, average speed= Total distance/ total time.

Let's assume t is the time taken for going from New Orleans to Boston and it's taking 1 hour less to return back. So, time taken for return back is t-1.

Given the speed from New Orleans to Boston is 40 mph. So,

Distance = Speed * time

So, d =40 t

Hence t= d/40

Similarly Distance for returning back:

d =80 (t-1)

d/80 = t-1 (Dividing 80 to each sides)

Now the total distance= d+ d = 2d

And total time : t + t -1= d/40 + d/80

So, the average speed =

= (cancel out d )

Common denominator of 40 and 80 is 80. So, multiply each terms by 80.

=

=

=

=53.33 mph

So, the average speed is 53.33 mph.

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