There are 90 ways to wear one necklace and one bracelet.
Step-by-step explanation:
The fundamental counting principle states that the number of possibilities in which multiple events can occur can be determined by multiplying the number of possible outcomes for each event. In other words, this principle states that if there are p ways to do one thing, and q ways to do something else, then there are p*q ways to do both.
In this case, if you have 6 bracelets and 15 necklaces, there are 6*15= 90 ways to wear one necklace and one bracelet.
