A machine in a factory has an error rate of 4 parts per 100. The machine normally runs 24 hours a day and produces 40 parts per hour. Yesterday the machine was shut down for 9 hours for maintenance.

How many error-free parts did it produce yesterday?

In a class of 37 students, 14 are taking German and 13 are taking Spanish. Of the students studying German or Spanish, 4 are taking both courses. How many students are not enrolled in either course?

Two sets of 3 consecutive positive integers have exactly one integer in common. The sum of the integers in the set with greater numbers is how much greater than the sum of the integers in the other set?