Using 2 CMD commands in dockerfile

When you use 2 CMD commands in docker file the last CMD command will be considered.
eg:

1. Write dockerfile with 2 CMD commands:

FROM ubuntu
MAINTAINER Rajesh Kumar << rajesh@scmgalaxy.com>>
ENV DEBIAN_FRONTEND=noninteractive
RUN apt-get update
RUN apt-get -y install tzdata
RUN apt-get install git -y && apt-get install -yq apache2
CMD echo "Hello world"
CMD ls

1. Building the dockerfile:
   [root@localhost docs]# docker build -t aswin1 -f doc38 .
   unable to prepare context: unable to evaluate symlinks in Dockerfile path: lstat /root/docs/doc38: no such file or directory
   [root@localhost docs]# docker build -t aswin1 -f doc8 .
   Sending build context to Docker daemon 10.75kB
   Step 1/8 : FROM ubuntu
   ---> a8780b506fa4
   Step 2/8 : MAINTAINER Rajesh Kumar << rajesh@scmgalaxy.com>>
   ---> Using cache
   ---> 88f6b6acfa81
   Step 3/8 : ENV DEBIAN_FRONTEND=noninteractive
   ---> Using cache
   ---> c8a76e7a5f98
   Step 4/8 : RUN apt-get update
   ---> Using cache
   ---> 4d9fe31bf152
   Step 5/8 : RUN apt-get -y install tzdata
   ---> Using cache
   ---> 41891c047aab
   Step 6/8 : RUN apt-get install git -y && apt-get install -yq apache2
   ---> Using cache
   ---> cfaefb036054
   Step 7/8 : CMD echo "Hello world"
   ---> Using cache
   ---> e3a33016f8d3
   Step 8/8 : CMD ls
   ---> Running in 39af03f7ea29
   Removing intermediate container 39af03f7ea29
   ---> 4ec90f2ffbdf
   Successfully built 4ec90f2ffbdf
   Successfully tagged aswin1:latest
   [root@localhost docs]# docker images
   REPOSITORY TAG IMAGE ID CREATED SIZE
   aswin1 latest 4ec90f2ffbdf 10 seconds ago 252MB

2. Running docker run command to create the container:
   [root@localhost docs]# docker run -itd aswin1
   837cffa37f38494cfdc264bb5da82b4f515834d850f2b23b822971230fe03022
   [root@localhost docs]# docker ps -a
   CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
   837cffa37f38 aswin1 "/bin/sh -c ls" 7 seconds ago Exited (0) 6 seconds ago keen_wright