MATH riddle that is stumping me

[thecoolnessrune]

I have a killer headache right now and i need to figure this out.. Here is the problem:

One day in the ancient kingdom of Montarek, a peasant saved the life of the kings daughter. The king was so grateful he told the peasant she could have any reward she desired. The peasant--- who was also the kingdoms chess champion-- made an unusual request:

"I would like you to place 1 ruba on the first square of my chessboard, 2 rubas on the second square, 4 on the third square, 8 on the fourth square, and so on, until you have covered all 64 squares. Each square should have twice as many rubas as the previous square."

Yes... this is 8th grade math... Normally I dont have a problem with this stuff but with this headache I simply cant think.. Can someone please give an equation for this to relate the squares (n) to rubas (r)?

Yeah it sounds noobish. But I promised him I'd help explain it to him later and in the mean time i have to get over this headache...

 

[her209]

2^n

 

[Hyperion042]

r = 2^(n-1)
Total = 2^n - 1

 

[thecoolnessrune]

I thought it was, but I simply couldn't check myself with this headache... thanks guys.. Feels like my head is about to unscrew..

 

[nissan720]

I heard the story it was rice... Finds paper

 

[crt1530]

Text

 

[episodic]

(n^2)-1=r

 

[nissan720]

The number it take to meet the need is:

18,446,744,073,709,551,615 grains of rice

I have no idea what the equation is but it was one of the handouts we got from my Direct Energy prof.

 

[episodic]

http://en.wikipedia.org/wiki/Ambalappuzha_Sri_Krishna_Temple

 

[BrownTown]

2^n - 1

Its pretty simple (esp. since any computer nerd should be shot if they don't know that), but since 2/3 of the answers before mine were wrong I decided to make sure everone is clear about it.

 

[RossGr]

On the first square you place a single grain of rice, that is 2^0 , on the second square 2 grains of rice is 2^1.

There are 64 squares so n runs from 1 - 64 so

r = 2^(n-1) = 2^63

 

[Merlyn3D]

Originally posted by: thecoolnessrune
I thought it was, but I simply couldn't check myself with this headache... thanks guys.. Feels like my head is about to unscrew..

We get it.....you have a really bad "headache". 🙂