diff --git a/Linux Shell/A Personalized Echo.sh b/Linux Shell/A Personalized Echo.sh
index be321acc..ae8c79d5 100644
--- a/Linux Shell/A Personalized Echo.sh	
+++ b/Linux Shell/A Personalized Echo.sh	
@@ -9,6 +9,8 @@
 #One line: "Welcome (name)" (quotation marks excluded).
 #The evaluation will be case-sensitive.
 
+#!/bin/bash
+
 read name
 echo "Welcome $name"
 
diff --git a/Linux Shell/Arithmetic Operations.sh b/Linux Shell/Arithmetic Operations.sh
index 0b8c163e..0c45c900 100644
--- a/Linux Shell/Arithmetic Operations.sh	
+++ b/Linux Shell/Arithmetic Operations.sh	
@@ -8,9 +8,9 @@
 
 # 17.929
 
+#!/bin/bash
+
 read p1
-read p2
-read p3
 
-printf "%.3f\n" `echo $p1 | bc -l`
+printf "%.3f\n" $(echo "$p1" | bc -l)
 
diff --git a/Linux Shell/Comparing Numbers.sh b/Linux Shell/Comparing Numbers.sh
index fd565128..b8e1e17f 100644
--- a/Linux Shell/Comparing Numbers.sh	
+++ b/Linux Shell/Comparing Numbers.sh	
@@ -16,6 +16,8 @@
 #- X is greater than Y
 #- X is equal to Y
 
+#!/bin/bash
+
 read firstNumber
 read secondNumber
 if (($firstNumber > $secondNumber)); then
diff --git a/Linux Shell/Getting started with conditionals.sh b/Linux Shell/Getting started with conditionals.sh
index 501cd690..fb191c96 100644
--- a/Linux Shell/Getting started with conditionals.sh	
+++ b/Linux Shell/Getting started with conditionals.sh	
@@ -11,5 +11,7 @@
 
 # echo YES or NO to STDOUT.
 
+#!/bin/bash
+
 read c
 [[ "$c" == [yY] ]] && echo "YES" || echo "NO"
diff --git a/Linux Shell/Let's Echo.sh b/Linux Shell/Let's Echo.sh
index 0ee50f1b..df77fa4b 100644
--- a/Linux Shell/Let's Echo.sh	
+++ b/Linux Shell/Let's Echo.sh	
@@ -8,4 +8,6 @@
 
 #HELLO
 
+#!/bin/bash
+
 echo "HELLO"
diff --git a/Linux Shell/Looping and Skipping.sh b/Linux Shell/Looping and Skipping.sh
index 716591c1..e5982614 100644
--- a/Linux Shell/Looping and Skipping.sh	
+++ b/Linux Shell/Looping and Skipping.sh	
@@ -11,9 +11,10 @@
 #.
 #99
 
+#!/bin/bash
 
 for i in {1..99..2}
 do
-    echo $i
+    echo "$i"
 done
 
diff --git a/Linux Shell/Looping with Numbers.sh b/Linux Shell/Looping with Numbers.sh
index 221b0fa8..ce16a202 100644
--- a/Linux Shell/Looping with Numbers.sh	
+++ b/Linux Shell/Looping with Numbers.sh	
@@ -15,6 +15,8 @@
 #.
 #50
 
+#!/bin/bash
+
 X=1
 while [ $X -le 50 ]
 do
diff --git a/Linux Shell/More on Conditionals.sh b/Linux Shell/More on Conditionals.sh
index 962ef47b..9ab72352 100644
--- a/Linux Shell/More on Conditionals.sh	
+++ b/Linux Shell/More on Conditionals.sh	
@@ -11,6 +11,7 @@
 
 # One word: either "SCALENE" or "EQUILATERAL" or "ISOSCELES" (quotation marks excluded).
 
+#!/bin/bash
 
 read c1
 read c2
diff --git a/Linux Shell/README.md b/Linux Shell/README.md
index a8a946a1..67529c60 100644
--- a/Linux Shell/README.md	
+++ b/Linux Shell/README.md	
@@ -1,6 +1,6 @@
 # Linux Shell
 
 
-- [Let's Echo](https://github.com/Aby-Sebastian/Hackerrank-Codes/blob/add-c/Linux%20Shell/Let's%20Echo.sh)
-- [Looping and Skipping](https://github.com/Aby-Sebastian/Hackerrank-Codes/blob/add-c/Linux%20Shell/Looping%20and%20Skipping.sh)
-- [Middle of a Text File](https://github.com/Aby-Sebastian/Hackerrank-Codes/blob/add-c/Linux%20Shell/Middle%20of%20a%20Text%20File.sh)
+-  [Let's Echo](https://github.com/Aby-Sebastian/Hackerrank-Codes/blob/add-c/Linux%20Shell/Let's%20Echo.sh)
+-  [Looping and Skipping](https://github.com/Aby-Sebastian/Hackerrank-Codes/blob/add-c/Linux%20Shell/Looping%20and%20Skipping.sh)
+-  [Middle of a Text File](https://github.com/Aby-Sebastian/Hackerrank-Codes/blob/add-c/Linux%20Shell/Middle%20of%20a%20Text%20File.sh)
diff --git a/Linux Shell/The World of Numbers.sh b/Linux Shell/The World of Numbers.sh
index 256614d7..722f90c8 100644
--- a/Linux Shell/The World of Numbers.sh	
+++ b/Linux Shell/The World of Numbers.sh	
@@ -8,6 +8,7 @@
 #Four lines containing the sum (X+Y), difference (X-Y), product (X*Y), and quotient (X/Y), respectively.
 #(While computing the quotient, print only the integer part.)
 
+#!/bin/bash
 
 read x
 read y