Answer 1

In each line, print not exactly <scale> chars, but at most <scale> chars, breaking at last word separator (whitespaces) or end of string.
You'll have to rethink the loop exit condition and how you slice the string.

Answer 2

First, think on how to find the indexes for the first and last printable word in each line, then print this slice. Hint: search whitespaces. Note how each line impacts the next.
Then, loop until the string finishes printing, not a fixed number of times.

Answer 3

Ash[Back In The Rhythm] Sorry I don't know Ruby. But while looking at your code I have discovered that you can remove the white space between the words that start on a new line.
Such as number in and voodoo prime
text = %{A Voodoo prime is a prime number whose reciprocal (in decimal) has the same numberin its digits. For example, 7 is a voodooprime because its reciprocal 1/7 = 0.14285714285 contains 7.}