I would like some help with election votes maths.

parties are

red, blue, green and pink

pop 201060
if there are 200000 votes in an election
200 are invalid Votes

Note: invalid votes are not counted below

red gets 9856 votes
Blue gets 89098 votes
green gets 50091 Votes
and pink gets 50755 votes

My questions are
1, How to I work out the percentage of each party so that the percent adds up to 100%
2, How do I workout when a party wins by getting 51 % of the vote.