correct a couple of typos in function descriptions/ instructions

2-mandatory/2-financial-times.js

@@ -11,7 +11,7 @@ function potentialHeadlines(allArticleTitles) {
 /*
     The editor of the FT likes short headlines with only a few words!
     Implement the function below, which returns the title with the fewest words.
-    (you can assume words will always be seperated by a space)
+    (you can assume words will always be separated by a space)
 */
 function titleWithFewestWords(allArticleTitles) {
     // TODO

2-mandatory/3-stocks.js

@@ -1,7 +1,7 @@
 /*
     THESE EXERCISES ARE QUITE HARD. JUST DO YOUR BEST, AND COME WITH QUESTIONS IF YOU GET STUCK :)
 
-    Imagine we a working for a finance company. Below we have:
+    Imagine we are working for a finance company. Below we have:
         - an array of stock tickers
         - an array of arrays containing the closing price for each stock in each of the last 5 days.
             For example, CLOSING_PRICES_LAST_5_DAYS_FOR_ALL_STOCKS[2] contains the prices for the last 5 days for STOCKS[2] (which is amzn)