Depends on the system you're using! Could me...
Do do re re do re do re do re mi re do re do do re do do
OR
La la si si la si la si la si do si la si la la si la la
Skittles they gotta taste the rainbow
1) 3 1/2 beats
Quarter note, eighth note, quarter note, quarter note
2) 2 beats and 1 rest
Quarter note, quarter note, rest
3) 2 beats, rest, 1 beat
Half note, rest, quarter note