Question

Megan buys 3 bracelets and 3 necklaces. Each bracelet costs 5. Megan pays on 40 and gets 4 change. what is the cost of one necklace?

Answer 1

The necklaces cost $3 each. 

Answer 2

40-4=36 <-- that's how much she spent.
3x5=15 <-- that's how much the bracelets cost
36-15=21 <-- that's how much she had left over
21/3=7 <-- that's how much one necklace costs

One necklace costs $7.