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How many cups of water do you need to serve your friends?

+1 vote
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You have a large number of friends coming over and they all get thirsty. Your first friend asks for 1/2 a cup of water. Your second friend asks for 1/4 a cup of water. Your third friend asks for 1/8 a cup of water, etc.

How many cups of water do you need to serve your friends?

posted May 13, 2015 by Anamika

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1 Answer

+2 votes

Sum of infinite GP , a/(1-r) , here a=r=1/2 ;;; a=first term ;;; r=common ratio

so answer is (1/2)/(1-(1/2)) == 1

answer May 13, 2015 by Ankit Kamboj



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There is an air base on the equator. The maximum amount of fuel that a plane can contain would be only sufficient for it to fly halfway around the world.

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Share your answer with detail explanation...

A trip around the world!
Logic Level 3

There is an air base on the equator. The maximum amount of fuel that a plane can contain would be only sufficient for it to fly halfway around the world.

For at least one plane to finish a trip around the world, how many planes do you need at least?

Details and assumptions:
Same plane doesn't depart twice or more.
The airplanes can use their fuel until it's empty. Starting the airplane doesn't take any time.
Every plane moves at the same speed, and on the same airway.
Assume the planes and air base are dimensionless, and thus, can turn directions instantly.
The plane can only be fueled via aerial refueling, and the amount of time the process takes is negligible.
Every plane starts at the air base and must return to the air base.

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