diff --git a/transform.Rmd b/transform.Rmd
index 69b995e..54ac76d 100644
--- a/transform.Rmd
+++ b/transform.Rmd
@@ -887,7 +887,7 @@ Functions that work most naturally in grouped mutates and filters are known as
     
 1.  Look at each destination. Can you find flights that are suspiciously
     fast? (i.e. flights that represent a potential data entry error). Compute
-    the air time a flight relative to the shortest flight to that destination.
+    the air time of a flight relative to the shortest flight to that destination.
     Which flights were most delayed in the air?
     
 1.  Find all destinations that are flown by at least two carriers. Use that