Ubuntu – How to solve “dpkg: error: 1 expected program not found in PATH or not executable”

I have installed the LAMP Server using the command sudo apt-get install lamp-server^. Thereafter, whenever I open the terminal the following error started to appear:

 bash: /home/gaja/.bashrccu: No such file or directory 
 bash: /home/gaja/.bashrc: line 4: syntax error near unexpected token (' 
 bash: /home/gaja/.bashrc: line 4: see /usr/share/doc/bash/examples/startup-files (in the package bash-doc)'

I could get rid of this problem using the answer given here.

However, now the problem is that I cannot install any thing using the sudo apt-get command.

I am trying to become root and then re-run the sudo apt-get install lamp-server^ command which gives the following error output:

dpkg: warning: 'tar' not found in PATH or not executable
dpkg: error: 1 expected program not found in PATH or not executable
Note: root's PATH should usually contain /usr/local/sbin, /usr/sbin and /sbin
E: Sub-process /usr/bin/dpkg returned an error code (2)

Following is the complete output of running the commands:

gaja@gaja-System-Product-Name:~$ sudo su
[sudo] password for gaja:

root@gaja-System-Product-Name:/home/gaja# sudo apt-get install lamp-server^
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Note, selecting 'libdbi-perl' for task 'lamp-server'
Note, selecting 'perl-modules' for task 'lamp-server'
Note, selecting 'libaprutil1-dbd-sqlite3' for task 'lamp-server'
Note, selecting 'perl' for task 'lamp-server'
Note, selecting 'apache2-bin' for task 'lamp-server'
Note, selecting 'libapache2-mod-php5' for task 'lamp-server'
Note, selecting 'ssl-cert' for task 'lamp-server'
Note, selecting 'mysql-server-5.5' for task 'lamp-server'
Note, selecting 'mysql-client-core-5.5' for task 'lamp-server'
Note, selecting 'libclass-isa-perl' for task 'lamp-server'
Note, selecting 'mysql-server' for task 'lamp-server'
Note, selecting 'libapr1' for task 'lamp-server'
Note, selecting 'php5-readline' for task 'lamp-server'
Note, selecting 'libaprutil1' for task 'lamp-server'
Note, selecting 'libwrap0' for task 'lamp-server'
Note, selecting 'libdbd-mysql-perl' for task 'lamp-server'
Note, selecting 'apache2-mpm-prefork' for task 'lamp-server'
Note, selecting 'libhtml-template-perl' for task 'lamp-server'
Note, selecting 'mysql-client-5.5' for task 'lamp-server'
Note, selecting 'libaio1' for task 'lamp-server'
Note, selecting 'mysql-common' for task 'lamp-server'
Note, selecting 'libmysqlclient18' for task 'lamp-server'
Note, selecting 'mysql-server-core-5.5' for task 'lamp-server'
Note, selecting 'libterm-readkey-perl' for task 'lamp-server'
Note, selecting 'php5-mysql' for task 'lamp-server'
Note, selecting 'apache2-data' for task 'lamp-server'
Note, selecting 'apache2' for task 'lamp-server'
Note, selecting 'php5-common' for task 'lamp-server'
Note, selecting 'php5-cli' for task 'lamp-server'
Note, selecting 'libswitch-perl' for task 'lamp-server'
Note, selecting 'libaprutil1-ldap' for task 'lamp-server'
Note, selecting 'tcpd' for task 'lamp-server'
libaio1 is already the newest version.
libapr1 is already the newest version.
libaprutil1 is already the newest version.
libaprutil1-dbd-sqlite3 is already the newest version.
libaprutil1-ldap is already the newest version.
libclass-isa-perl is already the newest version.
libdbd-mysql-perl is already the newest version.
libdbi-perl is already the newest version.
libhtml-template-perl is already the newest version.
libswitch-perl is already the newest version.
libterm-readkey-perl is already the newest version.
libwrap0 is already the newest version.
perl is already the newest version.
perl-modules is already the newest version.
ssl-cert is already the newest version.
tcpd is already the newest version.
apache2 is already the newest version.
apache2-bin is already the newest version.
apache2-data is already the newest version.
apache2-mpm-prefork is already the newest version.
libapache2-mod-php5 is already the newest version.
libmysqlclient18 is already the newest version.
mysql-client-5.5 is already the newest version.
mysql-client-core-5.5 is already the newest version.
mysql-common is already the newest version.
mysql-server is already the newest version.
mysql-server-5.5 is already the newest version.
mysql-server-core-5.5 is already the newest version.
php5-cli is already the newest version.
php5-common is already the newest version.
php5-mysql is already the newest version.
php5-readline is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 230 not upgraded.
2 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Do you want to continue [Y/n]? y
dpkg: warning: 'tar' not found in PATH or not executable
dpkg: error: 1 expected program not found in PATH or not executable
Note: root's PATH should usually contain /usr/local/sbin, /usr/sbin and /sbin
E: Sub-process /usr/bin/dpkg returned an error code (2)

root@gaja-System-Product-Name:/home/gaja# sudo apt-get install apache2
Reading package lists... Done
Building dependency tree       
Reading state information... Done
apache2 is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 230 not upgraded.
2 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Do you want to continue [Y/n]? y
dpkg: warning: 'tar' not found in PATH or not executable
dpkg: error: 1 expected program not found in PATH or not executable
Note: root's PATH should usually contain /usr/local/sbin, /usr/sbin and /sbin
E: Sub-process /usr/bin/dpkg returned an error code (2)
root@gaja-System-Product-Name:/home/gaja# 

Some of the troubleshooting steps that I have taken on suggestion of other members:

$ ls -l /bin/tar
ls: cannot access /bin/tar: No such file or directory

$ apt-cache policy tar
tar: Installed: 1.26+dfsg-8 Candidate: 1.26+dfsg-8 Version table: *** 1.26+dfsg-8 0 500 in.archive.ubuntu.com/ubuntu saucy/main i386 Packages 100 /var/lib/dpkg/status

I have also tried running the following command after switching to root, but that doesn't help either:

export PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games