1) Write me a perl program that counts from 1 ... 10. It must start at 1 and end at 10.

2) The file '/tmp/foo' consists of lines of text, each with a ':'. Write me a perl program that opens a file '/tmp/foo', and prints every line. The text should be reversed, as shown below

a:b	b:a
abcd:efgh	efgh:abcd
xxxyyy:z	z:xxxyyy
1:2:3	3:1:2

3) Assume there is an array named 'a'. This array contains numbers. Write me a program fragment that prints the average of the array.

4) Write me a SUBROUTINE named foo. This subroutine takes one argument, and prints either a 'yes' or 'no' depending on wether the file named buy the argument exists.