Duty Cycle

Suppose that a single cycle consists of transmission of a brief pulse of power followed by a 'quiet' time.

If the pulse width of the power transmitted is .000010 seconds
and
there are 500 cycles every second (500 Hz),
what is the total time in one second that power is being transmitted ?

The term Duty Cycle refers to the fraction of the cycle that the power is transmitted.
Clearly this is

.005

because we calculated .005 seconds total during a 1 second time duration.