Let the registered voters be 100. units
Since, 75% voters casted votes, therefore,
Total no. of voters =75%×100=75 units
Now, out of this, no. of valid votes =98%×75=73.5 units
Since, candidate one got 75% of votes, therefore the other candidate got 25% of votes.
Hence, no. of votes candidate one got =75%×73.5=55.125 units
According to the question,
55.125 units =9261 votes
⇒1 units =926155.125 votes
⇒100 units =926155.125×100 votes
Therefore, total registered votes is 16800