1. It's Duple Meter which means 2 beats per a bar, in the first and second bar, add a quarter note in the blanks. The third bar is a full bar rest or a half note
2. Triple Meter is 3 beats per bar. The first two bars add a half note. The last bar add a quarter note.
3. Quadruple Meter means 4 beats per bar. In the first bar add two quarter notes as beats 2 and 3 cannot be together. The second bar add a half note and the last bar add one quarter note and one half note