diff --git a/programming/exercises/boolean_logical_indexing.tex b/programming/exercises/boolean_logical_indexing.tex
index 5e790b2..f166f3d 100644
--- a/programming/exercises/boolean_logical_indexing.tex
+++ b/programming/exercises/boolean_logical_indexing.tex
@@ -1,4 +1,4 @@
-\documentclass[12pt,a4paper,pdftex]{exam}
+\documentclass[12pt,a4paper,pdftex, answers]{exam}
 
 \usepackage[german]{babel}
 \usepackage{natbib}
diff --git a/programming/exercises/signal.mat b/programming/exercises/signal.mat
new file mode 100644
index 0000000..d86a2f8
Binary files /dev/null and b/programming/exercises/signal.mat differ