There is a large market in Brisbane for private tutoring for Year 11 and 12 high school students. The market clearing price for the tutors is $40 per hour. Assume that 10 tutors are employed and each supplies one hour of labour a day. If the private tutors follow a linear, upward sloping supply curve and the smallest opportunity cost for offering their service is $21 per hour (when quantity supplied equals zero), what is the producer surplus for all tutors to the nearest whole number (with no decimal places)?