Synced instructions from problem specifications.

Author: BethanyG

exercises/practice/matching-brackets/.docs/instructions.md

@@ -1,3 +1,4 @@
 # Instructions
 
 Given a string containing brackets `[]`, braces `{}`, parentheses `()`, or any combination thereof, verify that any and all pairs are matched and nested correctly.
+The string may also contain other characters, which for the purposes of this exercise should be ignored.

exercises/practice/say/.docs/instructions.md

@@ -48,13 +48,3 @@ Put it all together to get nothing but plain English.
 `12345` should give `twelve thousand three hundred forty-five`.
 
 The program must also report any values that are out of range.
-
-### Extensions
-
-Use _and_ (correctly) when spelling out the number in English:
-
-- 14 becomes "fourteen".
-- 100 becomes "one hundred".
-- 120 becomes "one hundred and twenty".
-- 1002 becomes "one thousand and two".
-- 1323 becomes "one thousand three hundred and twenty-three".

exercises/practice/simple-cipher/.docs/instructions.md

@@ -9,7 +9,7 @@ If anyone wishes to decipher these, and get at their meaning, he must substitute
 —Suetonius, Life of Julius Caesar
 
 Ciphers are very straight-forward algorithms that allow us to render text less readable while still allowing easy deciphering.
-They are vulnerable to many forms of cryptanalysis, but we are lucky that generally our little sisters are not cryptanalysts.
+They are vulnerable to many forms of cryptanalysis, but Caesar was lucky that his enemies were not cryptanalysts.
 
 The Caesar Cipher was used for some messages from Julius Caesar that were sent afield.
 Now Caesar knew that the cipher wasn't very good, but he had one ally in that respect: almost nobody could read well.
@@ -29,9 +29,9 @@ When "ldpdsdqgdehdu" is put into the decode function it would return the origina
 
 ## Step 2
 
-Shift ciphers are no fun though when your kid sister figures it out.
+Shift ciphers quickly cease to be useful when the opposition commander figures them out.
+So instead, let's try using a substitution cipher.
 Try amending the code to allow us to specify a key and use that for the shift distance.
-This is called a substitution cipher.
 
 Here's an example:
 

exercises/practice/space-age/.docs/instructions.md

@@ -16,4 +16,10 @@ be able to say that they're 31.69 Earth-years old.
 
 If you're wondering why Pluto didn't make the cut, go watch [this YouTube video][pluto-video].
 
+Note: The actual length of one complete orbit of the Earth around the sun is closer to 365.256 days (1 sidereal year).
+The Gregorian calendar has, on average, 365.2425 days.
+While not entirely accurate, 365.25 is the value used in this exercise.
+See [Year on Wikipedia][year] for more ways to measure a year.
+
 [pluto-video]: https://www.youtube.com/watch?v=Z_2gbGXzFbs
+[year]: https://en.wikipedia.org/wiki/Year#Summary