Basics problems of Induction motor

The frequency of the induced rotor currents in the rotor of a 60 Hz induction
machine is 2 Hz. Furthermore, the fields in the air gap turn at -40 rpm with respect to the rotor.
(a) Find the number of poles.
(b) Find the slip of the motor.
(c) Find the synchronous speed in rpm.
(d) Find the motor speed in rpm.
(e) Is this a motor or a generator? Explain.