The table below provides information about the number of registered voters and the percentage of registered voters who voted in a particular election in three different centers. P, Q, and R. Centre   Total No. of registered voters Percentage of people who voted (out of the total no. of registered voters) P 3200 90 Q 1850 80 R 2500 66 What percentage of the total number of voters registered at center Q cast invalid votes, if the number of votes castes at centre Q was 25% of all votes cast at the centre?

25% 40% 20% 75%

20%