Brenda’s best friend is having a destination wedding, and the event will last three days. Brenda has $500 in savings and can earn $15 an hour babysitting. She expects to pay $350 airfare, $375 for food and entertainment, and $60 per night for her share of a hotel room (for three nights). How many hours must she babysit to have enough money to pay for the trip? Write the answer in interval notation.