This is a quarter note worth one count. There are four quarter notes in one bar of * time.
In this example the right and left hands alternate on the snare drum. This is a called a "single stroke roll".
This is a quarter note rest which indicates one beat of silence.
In this example the right hand plays a steady quarter note pulse on the hi-hat and the left hand plays the snare drum in unison on beats two and four.
In this example the right hand plays a steady quarter note pulse on the hi-hat while the right foot plays the bass drum in unison on beats one and three.
The bass drum and snare drum alternate in this example.
This example requires three way co-ordination.