George has a small coin collection. he has collected 16 gold coins, 28 silver coins, 32 copper coins, and4 bronze coins. at a flea market, george sells 15% of his coins. find the number of coins he sold.

This problem  can easily confuse people who are easily confused.

It makes absolutely no difference how many of each kind of coin he had. The
only important fact is that he had (16 + 28 + 32 + 4) = 80 coins all together.

He sold 15% of them.  ' 15% ' means ' 0.15 ', and ' of ' means ' times '.

0.15 x 80 = 12 coins sold.