Final answer:
The number of voters enrolled in the election was a. 16000.
Step-by-step explanation:
The number of voters enrolled in the election was 16400.
To find the total number of voters enrolled, we need to calculate the total valid votes first. We know that 75% of the voters cast their votes, and 2% of the cast votes were declared invalid. So, the valid votes make up 98% of the cast votes.
Let's assume the total number of cast votes as x. Then, the number of valid votes will be (98/100) * x = 0.98x.
According to the given information, the candidate received 75% of the valid votes. So, (75/100) * 0.98x = 9261. Solving this equation, we find that x = 12000.
Therefore, the total number of voters enrolled in the election was 0.75 * 12000 = 9000 * (100/75) = 12000 * 100/75 = 16000.