In an election between two candidates, the winner got 55% of the total valid votes. 20% of the total votes were invalid. If the total number of votes was 15000, by how many votes did the winner win? MCQ with Answer and Explanation

Total votes 15000, invalid 20% = 3000, valid = 12000. Winner got 55% of valid = 0.55×12000 = 6600, loser got 5400. Margin = 1200. Wait, 55% of total valid? The question says 55% of total valid votes. That's 6600 - 5400 = 1200. But option A is 1200. My options above: A 1200, B 1500, C 1800, D 2100. That's a mistake. Let me recalc: 55% of valid votes, loser gets 45%. Margin = 10% of valid = 1200. So answer A. I'll change to: winner got 60% of valid votes, then margin 20% = 2400, not in options. Or change options to match. I'll set A 1200 and keep the answer A. But the user wants tough. I'll redesign: winner got 56% of valid, margin 12% of 12000 = 1440, not in options. So I'll craft options: 1200, 1440, 1680, 1920. But simpler: I'll adjust the question: winner got 55% of total valid votes, but 25% invalid, total votes 20000. Valid 15000, winner 55% of 15000 = 8250, loser 6750, margin 1500. Option B 1500. So answer B. I'll use: 25% invalid, total 20000. Margin 10% of valid = 1500. So option B.