62% of the registered voters in state W declared themselves

not the first time when I say it, but Solve the paradox is one of my favorite type of questions on CR.

62% of the registered voters in state W declared themselves Democrats. Despite this, for the past 3 elections, the citizens of state W have voted a Republican into the office as governor.

ok, so 62% of voters are D.
nevertheless, last 3 E -> republicans won.

how come so?

well, if to pre-think, it might be the case that voters who declared themselves democrats did not vote.

moreover, for paradox type of questions, we can use the below formula:

Because -correct answer choice-, Republicans won, while 62% of registered voters are Democrats.


A) Approximately 78% of the rural residents of state W decalred themselves republicans, as compared with 38% of the urban residents.
irrelevant. we are told that 62% of all voters in the state are democrats. so it is all together rural+urban. thus, out.

B) State elections consist of a primary election in which voters must vote for a candidate matching their declared party followed by a general election in which voters can vote for a candidate of any party.
well, this is confusing. state elections - first vote for candidate matching declared party, but then there is general election, in which people can vote for candidates of any party.
but we are interested in elections for governor. what does this all have to do with state/general election? suspect, but let's check other answer choices.

C) Over the past 5 elections, the percentage of declared republicans who voted was significantly higher than the percentage of declared democrate who voted.
aha, so if more republicans than democrats actually voted, then the triumph of the republican candidates is thus explained. this one looks better than suspicious B, so B can be eliminated.

D) Voters must declare a party of preference more than thirty days before the state' primary election, and voters with no declared preference are ineligible to vote in the primary.
this one is irrelevant, as it does not help to explain the discrepancy.

E) The state's last democratic governor was initially very popular but lost his bid for re-election after the state's economy suffered a severe recession.
last democratic governor - well, from the beginning out. it does not explain the discrepancy.

few more words on C.
suppose we have 1000 voters, 620 of the voters are democrats, 380 are republicans. if during the elections participated only 310 democrats while 380 republicans, then democrats have no way to win the elections. since we are told that out of the people who actually voted were more republicans, it means that not all the registered democrats actually voted.
C so far is the best answer.