diff --git a/lib/practice_exercises.rb b/lib/practice_exercises.rb
index 291e4e6..e127002 100644
--- a/lib/practice_exercises.rb
+++ b/lib/practice_exercises.rb
@@ -1,13 +1,43 @@
 
-# Time Complexity: ?
-# Space Complexity: ?
+# Time Complexity: OofNsquared bc delete_at takes up ALOT of space (so says my tutor)
+# Space Complexity: Oof1 constant bc were not adding to it, we're subtracting
 def remove_duplicates(list)
-  raise NotImplementedError, "Not implemented yet"
+  i = 0
+  list.length.times do |num|
+    if list[i] == list [i + 1] #if this matches its neighbor...
+      list.delete_at(i +1)  #...delete it!
+    else
+      i += 1 #move on
+    end 
+  end
+  return list 
 end
 
-# Time Complexity: ?
-# Space Complexity: ?
+#hi chris, this one boggled my mind, dont mind my notes. 
+# Time Complexity: OofNsquared *maybe?
+# Space Complexity: OofN
 def longest_prefix(strings)
-  raise NotImplementedError, "Not implemented yet"
-end
+  prefix = "" #where the prefix is gonna end up
+  i = 0 #always start here :]
+  
+  while i < strings[0].length #from array - starting at the beginning of the word 
+    j = strings[0][i] #get index of word @ letter
+    k = 0 #counter For same letters #lets see how far we get
+    
+    strings.each do |string| #lets look and see whats up
+      if j == string[i] #does j[letter] match index of letter of comparable string?
+        k += 1 # If it does, it increments here!
+      end
+    end
+    
+    if k == strings.length #comparing matches against length
+      prefix += j #adds letter if it finds a match
+    else 
+      break #gotta exit loop
+    end
+    i += 1 #index moves on
+  end
+  return prefix #boom boom
+  
+end #end of method