Election voting questions in Percentage

 In an election only two candidates contested. 30 % of the registered voters did not cast their votes and 180 votes were declared invalid. The winner got 684 votes more than his opponent. The number of valid votes received by the winner is 42% of the number of registered voters. How many registered voters cast their votes? for video solution click this video

this same question can be asked in the below manner

question
In an election only two candidates contested 20% of the voters did not vote and 120 votes were declared as invalid. The winner got 200 votes more than his opponent  thus he secured 41% votes of the total voters on the voter list. Percentage votes of the defeated candidate out of the total votes casted is
ans 45 %