Math Is Fun Forum

Skylee

Member

Registered: 2009-06-09

Posts: 2

Simple problem,that I keep messing up.

Okay, so to make this short and simple, I am doing a case mod on a computer case. It is going to be part light bright, and part translucent legos.

This is the case(in case you're curious): http://www.newegg.com/Product/Product.aspx?Item=N82E16811148001&nm_mc=TEMC-RMA-Approvel&cm_mmc=TEMC-RMA-Approvel-_-Content-_-text-_-

The measurements are: 18.5" x 8.2" x 17.5"(D x W x H)
The light bright base is: 12x12
The legos I want to use: 1x2 (transparent red base)
I just need to know how many of the 1x2 legos I would need to cover: the right side, the left side, and the top

The back,front, and bottom need to be excluded, as well as the 12x12 section of light bright.

I have tried many ways of calculating it but I keep coming up with bogus answers, that just don't sound right.

If anyone could explain how to find out how many legos I will need, please help me out! My computer comes in just a few more days, and I would like to start modding as soon as possible! Thanks a bunch!

~Skylee~

Ricky

Moderator

Registered: 2005-12-04

Posts: 3,791

Re: Simple problem,that I keep messing up.

I just need to know how many of the 1x2 legos I would need to cover: the right side, the left side, and the top

The back,front, and bottom need to be excluded, as well as the 12x12 section of light bright.

You contradicted yourself here.  At first you say you just want the number to cover the right, left and top.  Then you seem to imply you want to cover part of the bottom to (specifically, the bottom minus the 12x12).  Assuming you don't want to cover the bottom:

Area of the right and left sides: D * H = 323.75
Area of the top: D * W = 151.7
Total area: 799.2

Area of a lego: 2

Number of legos needed: 799.2 / 2 = 399.6 ~ 400.  I would buy 500 to be safe since legos will not fit exactly.

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"In the real world, this would be a problem.  But in mathematics, we can just define a place where this problem doesn't exist.  So we'll go ahead and do that now..."

Ricky

Moderator

Registered: 2005-12-04

Posts: 3,791

Re: Simple problem,that I keep messing up.

Better estimate.  This number should be optimal (save actually trying to cut the darn things).

171 legos (each) for the left and right, but in order to get this the legos must be oriented so that they are taller than they are wide.

90 legos for the top, they must be oriented so that they are deeper than they are wide.

Total legos: 432.

---

"In the real world, this would be a problem.  But in mathematics, we can just define a place where this problem doesn't exist.  So we'll go ahead and do that now..."

Skylee

Member

Registered: 2009-06-09

Posts: 2

Re: Simple problem,that I keep messing up.

Thanks a bunch!

and no, I do not want to cover the bottom =P