I disagree with those arguing that rejected (spoilt or disputed) votes should be isolated in computing the final Presidential results-- Okiya Omtatah Okoiti...

 In mathematics, a percentage is a way of expressing a number as a fraction of the whole or of 100 (per cent meaning "per hundred"). If a basket has 100 apples and 10 are bad, then 10% are bad. If one eats 50 apples out of the basket, then he will have eaten 50% of the 100 apples. It will be wrong for one to claim that he ate 55.6% of the apples in the basket, and that the remaining 40 apples account for 44.4%, since only 90 apples were good. That would be accounting for only the 90 good apples whereas the basket had 100 apples, including 10 bad ones.

Likewise, the votes cast include both valid and spoilt votes. Any ballot paper that was ripped out of the ballot book was a cast vote, even if the individual voter shredded it. And 50% + 1 of votes must be calculated out of the cast votes, not the valid votes.

From the Constitution:
(i) Article 86(b) is categorical that: "At every election, the Independent Electoral and Boundaries Commission shall ensure that— the votes cast are counted, tabulated and the results announced promptly by the presiding officer at each polling station;"

(ii) Article 138(4) "A candidate shall be declared elected as President if the candidate receives— (a) more than half of all the votes cast in the election; and (b) at least twenty-five per cent of the votes cast in each of more than half of the counties."

I think the law is very clear that it is the percentage of the cast votes which determines the winner, and not the percentage of the valid votes.

God bless.

Omtatah