diff --git a/src/SolutionsTo50.hs b/src/SolutionsTo50.hs
index 5e9c0c7..6c372c5 100644
--- a/src/SolutionsTo50.hs
+++ b/src/SolutionsTo50.hs
@@ -29,12 +29,21 @@ solutionsTo50_ n = case n of
     18 -> solution18
     _  -> putStrLn "Solution not present in program"
 
+-- | Solves Project Euler Problem 1:
+-- Find the sum of all the multiples of 3 or 5 below 1000.
+-- This is solved by taking the union of multiples of 3 and 5 and summing them.
 solution1 :: Integer
 solution1 = sum $ union [3,6..999] [5,10..999]
     
+-- | Solves Project Euler Problem 2:
+-- By considering the terms in the Fibonacci sequence whose values do not exceed four million,
+-- find the sum of the even-valued terms.
 solution2 :: Integer
 solution2 = sum . filter even $ takeWhile (<= 4000000) fibs
   
+-- | Solves Project Euler Problem 3:
+-- Find the largest prime factor of the number 600851475143.
+-- This is solved by generating prime factors and finding the maximum.
 solution3 :: Integer
 solution3 = let primes = 2 : filter (null . tail . primeFactors) [3,5..]
                 primeFactors n = factor n primes
@@ -44,27 +53,42 @@ solution3 = let primes = 2 : filter (null . tail . primeFactors) [3,5..]
                           | otherwise      =     factor n ps
             in  maximum $ primeFactors 600851475143
                   
+-- | Solves Project Euler Problem 4:
+-- Find the largest palindrome made from the product of two 3-digit numbers.
+-- This is solved by iterating through products of 3-digit numbers and checking for palindromes.
 solution4 :: Integer
 solution4 = maximum [x | y<-[999,998..100], z<-[999,998..y], let x = y*z, isPalindromic x]
 
+-- | Solves Project Euler Problem 5:
+-- What is the smallest positive number that is evenly divisible by all of the numbers from 1 to 20?
+-- This is solved by finding the least common multiple (LCM) of numbers from 1 to 20.
 solution5 :: Integer
 solution5 = foldr1 lcm [1..20]
   
+-- | Solves Project Euler Problem 6:
+-- Find the difference between the sum of the squares of the first one hundred natural numbers and the square of the sum.
 solution6 :: Integer
 solution6 = sumSquare - squareSums
   where squareSums = sum $ map (^2) [1..100]
         sumSquare = (^2) $ sum [1..100]
                 
+-- | Solves Project Euler Problem 8:
+-- Find the thirteen adjacent digits in the 1000-digit number that have the greatest product.
 solution8 :: Integer
 solution8 = maximum . map product . takeWhile (\l -> length l >= 13) . map (take 13) . tails $ digitArr
   where digitArr = map digitToInt digitString
 
+-- | Solves Project Euler Problem 13:
+-- Work out the first ten digits of the sum of the following one hundred 50-digit numbers
+-- (stored in p13numbers.txt).
 solution13 = do
   numbers <- fmap ( map read . lines ) (readFile "p13numbers.txt")                
   putStrLn . take 10 . show . sum $ numbers
   
 
   
+-- | Solves Project Euler Problem 18:
+-- Find the maximum total from top to bottom of the triangle (stored in triangle.txt).
 solution18 = do  
   a <- answer
   putStrLn $ show a