Well's mother sells watermelons, peppers, and oranges at the local store. A watermelon costs three times what each pepper costs. An orange costs 5 less than what a watermelon cost. Dillon is sent to the store to buy 4 watermelons, 20 peppers, and 10 oranges. What's the total amount of money he will spend if each pepper costs 15$?
Work out the solution step by step.