Abracelet wa marked up $50 from cost which amounts to a 20% increase find the original cost of the bracelet

I believe this is one of those "Find the original cost of the item" bracelets. If so, this is a simple process.

You have a bracelet that is NOW 50 dollars after a 20% increase in price. Who knows, maybe somebody lost some stocks, but now you need to know what the original price of this item was.

So, you have two numbers. $50, and 20%. You can't do anything with the 20% as it is, so you need to convert it to a decimal, which you do so by always moving the percent sign (%) two places to the left, and replacing it with a decimal sign (.)
You get .20
NOW, you must find out how much of a difference there was between the new price and old price. You can do just this by simply multiplying your NEW ($50) cost by your converted percentage. 
50*.20=10 (carry the dollar sign from the 50 down)
This means there is a $10 difference in bracelet's old price and new price. You know there was an increase, so this means you now need to subtract 10 from 50 and you'll get your old price.
50-10=40

The bracelet's original price was $40. Bless the heart of whoever in management lost their stocks (joke).

If you want to check this, just simply add the difference and the old price together, if you get the new price, then you're correct. 10+40=50, so this is indeed correct.

~Hope this helps m8!