diff --git a/.~lock.Chapter-4-questions-problems-cases.odt# b/.~lock.Chapter-4-questions-problems-cases.odt#
new file mode 100644
index 0000000..2a827db
--- /dev/null
+++ b/.~lock.Chapter-4-questions-problems-cases.odt#
@@ -0,0 +1 @@
+,bdumontelle,debian04.cis.com,27.02.2019 07:39,file:///home/bdumontelle/.config/libreoffice/4;
\ No newline at end of file
diff --git a/Chapter-4-questions-problems-cases.odt b/Chapter-4-questions-problems-cases.odt
index 7a804ea..a2ccdcf 100644
Binary files a/Chapter-4-questions-problems-cases.odt and b/Chapter-4-questions-problems-cases.odt differ