what is the average speed ?

A plane maintains an average speed of 285mph from London to New York. It then returns from New York to London at an average speed of 76mph. What is the average speed for the entire journey?

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suresh

120 is the answer?

Yes jainbrijesh.....Plz leave your solution...

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suresh

let distance=d,
av.speed1=v1=285
time=t1,
d=285*t1

here again distance=d
av. speed2=v2=76
time=t2
d=76*t2

now: 285*t1=76*t2
t2=(285/76)*t1

Now av. speed=2d/(t1+t2)

solve it and get the answer 120.

Very Good Explanation buddy.....

Keep it up.....:)

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suresh