So, Valencia, you should realize quickly that 3/4 of the jewelry is necklaces or pins, since 1/2 + 1/4 = 3/4.
This means that the 16 bracelets and rings are the other 1/4 of the jewelry.
If 16 is 1 part of 4, then each of the 4 parts is 16 and there are 64 pieces of jewelry altogether.
Hope this helps!