diff --git a/OS/bash/Week3/q3.sh b/OS/bash/Week3/q3.sh
new file mode 100644
index 0000000..85ae1a2
--- /dev/null
+++ b/OS/bash/Week3/q3.sh
@@ -0,0 +1,11 @@
+#!/bin/sh
+
+echo "Changing all files with .txt to .text"
+x=`find . -type f -iname "*.txt"` 
+for i in $x;do
+j=`echo "$i" | cut -d '.' -f 2`
+echo $j
+mv $i ./$j.text
+done
+
+
diff --git a/OS/bash/Week3/q4.sh b/OS/bash/Week3/q4.sh
new file mode 100644
index 0000000..8c63f81
--- /dev/null
+++ b/OS/bash/Week3/q4.sh
@@ -0,0 +1,8 @@
+#!/bin/sh
+
+echo "Enter Basic Salary"
+read basic
+echo "Enter TA"
+read TA
+GA=$(echo "$basic + $TA + 0.1*$basic" | bc -l)
+echo "$GA"
diff --git a/OS/bash/Week3/q4_1000.sh b/OS/bash/Week3/q4_1000.sh
new file mode 100644
index 0000000..2b9fa95
--- /dev/null
+++ b/OS/bash/Week3/q4_1000.sh
@@ -0,0 +1,10 @@
+#!/bin/sh
+
+echo "Enter Basic Salary"
+read basic
+echo "Enter TA"
+read TA
+GA=$(echo "$basic + $TA + 0.1*$basic" | bc -l)
+for i in $(seq 1 1000);do
+echo "$GA"
+done
diff --git a/OS/bash/Week3/q5.sh b/OS/bash/Week3/q5.sh
new file mode 100644
index 0000000..0841242
--- /dev/null
+++ b/OS/bash/Week3/q5.sh
@@ -0,0 +1,18 @@
+#!/bin/sh
+
+echo "Enter the file extension"
+read ext
+
+echo "Enter the destination folder"
+read dest
+
+mkdir -p "$dest"
+
+files=$(find . -maxdepth 1 -type f -name "*.$ext")
+echo "$files"
+
+for file in $files; do
+	cp "$file" "$dest"
+done
+
+echo "Successfully copied files to target directory"
diff --git a/OS/bash/Week3/q6.sh b/OS/bash/Week3/q6.sh
new file mode 100644
index 0000000..c11b494
--- /dev/null
+++ b/OS/bash/Week3/q6.sh
@@ -0,0 +1,9 @@
+#!/bin/bash
+
+for file in *;do
+if [ -f "$file" ];then
+sed -i -E 's/(^|\.)ex:/\1Exammple:/g' "$file"
+fi
+done
+
+echo "File modified"