Analysis - How many numbers in the interval [0,1) contain 5 consecutive 5's?

glacier302
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Homework Statement



Let E be the set of points in [0,1) whose decimal expansion contains somewhere the block 55555. Find the measure of E.


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The Attempt at a Solution



I have a feeling that in order to find the measure of E, I should find the measure of the complement of E and then subtract it from 1. The complement of E would be the points in [0,1) containing no 5's, containing no consecutive 5's, containing 2 consecutive 5's, containing 3 consecutive 5's, containing 3 consecutive 5's, or containing 4 consecutive 5's. I'm not sure how to compute the measure of this set, however.

Any help would be greatly appreciated!
 
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Well, start your program. What the measure of all of the points that contain no 5's at all? This is rather like a Cantor set.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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