Exercise 1-15. Zachary made plans to visit a friend in New York during the Memorial Day weekend. However, before the trip, his employer asked him if he would work overtime for 6 hours during the weekend. Zachary's normal rate is $20. Overtime is paid at a rate of time-and-a-half. What will be the opportunity cost if Zachary decides to visit his friend in New York? Enter your answers as amounts only with neither commas nor decimals.