In an election, 30% of the voters voted for candidate A whereas 60% of the remaining voted for candidate B. The remaining voters did not vote. If the difference between those who voted for candidate A and those who did not vote was 1200, how many individuals were eligible for casting vote in that election ?

Answer: Option C

Let the number of persons eligible to vote be x
Then, votes who voted for A = 30% of x
Votes who voted for B = 60% of (70% of x)
= $$\left(\frac{60}{100}\times \frac{70}{100}\times 100\right)$$   % of x
= 42% of x
Voters who did not vote = [100 - (30 + 42)]% of x = 28% of x
∴ 30% of x - 28% of x = 1200
⇒ 2% of x = 1200
⇒ x = $$\left(\frac{1200\times 100}{2}\right)$$
⇒ x = 60000