SOLUTION: Using numbers 1 3 5 7 9 11 13 17 19 in 5 steps sum should be 30.We can repeat numbers.

This is a trick question.  It makes you think that you are to add 5
of those and get 30.  That's impossible. Here's why:

Any ODD number of ODD numbers will always have an ODD sum.  Since all 
those numbers are ODD and if you were to use an ODD number, 5, of them, 
you would always get an ODD number.  Since 30 is EVEN, you would never get
a sum of 30 by adding 5 ODD numbers.  So if that were what you were asked
to do, it would be impossible.
  
It's a trick question. You weren't asked to add only 5 numbers. You
were asked to use only 5 STEPS. and adding 6 numbers only requires 5 steps.

Since you can repeat numbers, we may as well use the fact that 30 = 5×6, or 

5+5+5+5+5+5=30

Step 1: Add the first two 5's, get 10
Step 2: Add the third 5, get 15
Step 3: Add the fourth 5, get 20
Step 4: Add the fifth 5, get 25
Step 5: Add the sixth 5, get 30

That's only 5 steps.  :) 

Edwin