diff --git a/04-pipefilter.md b/04-pipefilter.md
index 1b183e9a8..dd7f81bed 100644
--- a/04-pipefilter.md
+++ b/04-pipefilter.md
@@ -6,16 +6,17 @@ exercises: 10
 
 ::::::::::::::::::::::::::::::::::::::: objectives
 
+- Explain the advantage of linking commands with pipes and filters.
+- Combine commands in more than one stages to get new output
 - Redirect a command's output to a file.
-- Construct command pipelines with two or more stages.
 - Explain what usually happens if a program or pipeline isn't given any input to process.
-- Explain the advantage of linking commands with pipes and filters.
 
 ::::::::::::::::::::::::::::::::::::::::::::::::::
 
 :::::::::::::::::::::::::::::::::::::::: questions
 
-- How can I combine existing commands to do new things?
+- How can I produce various forms of the output of existing commands? How to show only part of the output? ( -> command line switches and pipes)
+- How can I combine existing commands to do new things? ( -> pipes)
 
 ::::::::::::::::::::::::::::::::::::::::::::::::::
 
diff --git a/md5sum.txt b/md5sum.txt
index 4968d50ca..572c7c006 100644
--- a/md5sum.txt
+++ b/md5sum.txt
@@ -6,7 +6,7 @@
 "episodes/01-intro.md" "f9424965b4e7855f0e569be741c5e88e" "site/built/01-intro.md" "2023-06-09"
 "episodes/02-filedir.md" "4d719c53b2f55b006cc88632d2189cb7" "site/built/02-filedir.md" "2024-03-08"
 "episodes/03-create.md" "cda7949aecf6bfe600e559f27319cc71" "site/built/03-create.md" "2024-03-08"
-"episodes/04-pipefilter.md" "880f2043f1b6d4febde2d4f6dd2c2a05" "site/built/04-pipefilter.md" "2024-01-17"
+"episodes/04-pipefilter.md" "0d922c8de8e6b5f484d3f9b5969f3f4b" "site/built/04-pipefilter.md" "2024-04-12"
 "episodes/05-loop.md" "fd0d4a3a3795930cc2e156b6e2b25a04" "site/built/05-loop.md" "2023-11-10"
 "episodes/06-script.md" "166572403e3b5f1c314ce7c52babb7b5" "site/built/06-script.md" "2023-08-05"
 "episodes/07-find.md" "b2c592366ea5a5c9a654ba13ec5765d1" "site/built/07-find.md" "2023-11-09"