need help!!!awk,grep,sed

Shell Programming and Scripting
1

hi all

by using cat /etc/passwd
I've got these output.

ajh1ect:x:839:501:Anthony:/home/ajh1ect:/bin/bash
mjb1ect:x:840:501:Michael:/home/mjb1ect:/bin/bash
mv3ect:x:841:501:Marian:/home/mv3ect:/bin/bash

now I want to see just the user ID and group ID.
so what is the code will be with using awk, grep or sed?

the output should be like (as I just want to see the user ID and group ID)

839:501
840:501
841:501

requesting all for help.

Thank You

2 
awk -F":" ' { print $3 ":" $4 } ' file

cut -d":" -f3,4 file
3

thanks a lot anbu23.
its working.