"Oh, that's easy."
We say this often when we help beginners with coding. I think we say this for several reasons, but one big reason is to encourage the beginner that he or she can solve the problem by reducing the perceived difficulty of the problem. However, in reality, this probably has an adverse effect. First of all, it's condescending. It puts the beginner's confidence down. He or she must be thinking, "If this is so easy, why can't I do it?" You might even be wrong that it's an easy problem. There may be details of the problem you haven't noticed yet that genuinely difficult problem look very easy.
I believe that you can omit saying "That's easy," completely and help out someone effectively. Just treat problems beginners have as a problem you and your colleagues have. Don't belittle the beginner with phrases like "That's easy" and just focus on what the problem is and helping them solve the problem.