Unfortunately all three components you calculated are incorrect.
1. ${10 \choose 4}$ insists on exactly four votes, not up to 4. You want ${10\choose 4}+{10\choose 3}+{10\choose 2}+{10\choose 1}+{10\choose 0}$.
2. ${8\choose 3}$ does not rank the three candidates, only chooses them. What you want is $(8)_3+(8)_2+(8)_1+(8)_0=8\times 7\times 6+8\times 7+8+1$.
3. ${5\choose 5}$ does not do anything, equalling 1. Ballots may be blank, hence each bond issue has three choices (accept, reject, blank). Hence, what you want is $3^5$.