Answer: 15 grams of cocoa
Work Shown:
30% = 30/100 = 0.30
30% of 50 = 0.30*50 = 15
Here's another way to think about it: If we had 100 grams of chocolate and 30% are cocoa, then we have 30 grams of cocoa by definition of what percentage means. Divide the 100 in half to get 50, so we'll have to divide the 30 in half to get 15.