Okay I'll make this short. I snorted cocain about 3-4 months ago just about 3 hits. Nothing big because I didn't buy it and I took about 4 hits of marihuana 60 days ago. Before that I smoked marijuana 2 years ago very very infrequent user of both. Will I pass a pre employment drug hair screen if I take it?

What do you mean IF you take it?

Its generally part of the hiring process with most employers these days... if you don't take it you automatically don't get the job.

I think it is more if it is required, or if they ask him to do it. Regardless the hair test is meant to test for habitual use. The drug will build up in the various excretions of your body, hair, nails, skin, and the like. The hair is the best because it sticks around the longest on your body. So if you're smoking, or snorting, up a storm than it will be positive. If you only, as you said, had a couple hits over the last few months than chances are you won't hit the cut off for a positive test.

A hair drug test is meant to show consistent use over time. A 1.5 inch sample, cut at the scalp line, will go back 90 days. With that small amount you used it is highly doubtful if you will show a positive.