Jackson's votes per 7 votes for Morris in mayoral election

[ScrewedIre]

Here's the question: Last year there were three candidates who ran for mayor, Morris, Jackson, and Victor. Out of a total of 12,320 votes, Jackson received 30% of the votes. If for ever 3 votes for Morris there were 5 votes for Victor, how many votes for Jackson were there for every 7 votes for Morris?

 

[MarkFL]

Jackson got 30% of the votes, which is 3,696 votes. This means that together, Morris and Victor got the remaining 70%, which is 8,624 votes. Morris got 3/8 of these (3,234 votes), while Victor got 5/8 (5,390) votes.

Now, the combined votes for Jackson and Morris is 6,930. Jackson got 8/15 of these votes, so what fraction did Morris get?