Chauncy, an English bulldog, received 1,618 votes in the Mr. Bulldog

Answer is B
Let T= Total
He got 20T/100
He need 30T/100. i.e. 10T/100 more.

Question is 10T/100 is ? % of remaining Votes
Remaining votes = 80T/100
10T/100= (?/100) of 80T/100.
?=12.5%

You have taken 10% of 8090, while the questions asks 809 is what % of the remaining votes. Hence B should be the correct answer as

809/6472*100 ~ 12.5%

"what percent of the remaining votes" - GMAT does trick its test taker...

To make total 30%, he needs 10% more votes of the total.

Let's suppose total is 100 and he needs 10% of 100= 10

But since the remaining votes are 80, 10 is 100*10/80%= 12.5%

B is the answer

Knowing the number of votes is not necessary.

\(\text{Remaining vote }= 100\% - 20\% = 80\%\)
\(\text{Additional votes needed }= 30\% - 20\% = 10\%\)
\(80\% \times n = 10\%\)
\(n = \frac{10\%}{80\%} \\= \frac{1}{8} = 0.125 = 12.5\%\)

If Chauncy has already won approximately 20 percent of the votes, then he would need 10 more percent of the votes to win 30 percent of the total votes. However, here we are speaking in terms of the remaining votes, i.e., the remaining 80 percent of the votes.

Since 10/80 = 1/8 = 12.5%, then he needs 12.5% of the remaining 80 percent of the votes in order to get the 10 more percent of the total votes, i.e., a total of 30 percent of all the votes.

Alternate Solution:

Assume 100 people are voting. Chauncy has already won 20%, or 20, of the votes, which means that 80 votes remain. Chauncy needs 10 more votes out of those 80 remaining votes, so he needs 10/80 = 1/8, or about 12.5% of the remaining votes.

Answer: B

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