diff --git a/ch2/applied.R b/ch2/applied.R
index 7cdc327..cc68fa3 100644
--- a/ch2/applied.R
+++ b/ch2/applied.R
@@ -43,6 +43,7 @@ dim(Auto)
 summary(Auto)
 
 # (a)
+sapply(Auto, class)
 # quantitative: mpg, cylinders, displacement, horsepower, weight,
 # acceleration, year
 # qualitative: name, origin