After reading the comments you have part one figured out, that is you have to show a total of 3 eighths, rests or notes in each bar and 2 sixteenths equal one eighth. From there it is simple math.
As for part 2, you are on the right track mathematically, both bars are missing a half note, or 2 beats. The thing to take into consideration is that time signatures with a multiple of 3 in the top position are grouped in threes of the bottom number value. That means that 6/4 is two groups of 3 quarter notes in one bar. Taking that into consideration and also looking at the spacing of the notes in bar 1, rather than a half note rest either at the beginning or end of the measure, the right choice is a quarter rest at the beginning and another at the end of the bar. This will clearly show the division of the two groups of 3 quarter notes. Bar 2 is more obvious, a half note rest at the end of the bar will make this complete and correct. The half rest could also be before the quarter note as well but the note spacing seems to favor it after the quarter note.