The Pizza Palace served 15 customers yesterday. 1/3 of the customers ordered breakfast. 3/5 of the remaining customers ordered dinner. The rest of the customers ordered take-out. How many customers ordered take-out?

1/15 of the customers ordered takeout

5/15 of the customers ordered breakfast
9/15 of the customers ordered dinner
add 9/15 and 5/15 to get 14/15 which would leave 1 customer. the one that ordered takeout.