Correct Answer - Option 5 : 15000
GIVEN:
% of voters who didn't cast their vote = 30%
invalid votes = 500
winner's share = 60% of valid votes
margin = 2000 votes
EXPLANATION:
let the total number of voters on the list be x
\(votes \space polled = 70\%\space of \space x\Rightarrow\frac{7}{10}\times x \\valid \space votes = \frac{7}{10}\times x - 500 \\winner's\space share =60\%\\loser's \space share = 40\% \\margin = 20\%\space of \space valid\space vote s \\\therefore\frac15\times[\frac{7}{10}\times x- 500]=2000 \\\Rightarrow x=15000\)
ALTERNATE SOLUTION:
let valid votes be 100
\(margin= 20\%\space of \space valid\space votes =2000 \\total\space valid\space votes =10000 \\votes\space polled =10000+500=10500 \\votes \space polled = 70\%\space of \space list \\\Rightarrow70\%=10500 \\\Rightarrow100\%=\frac{10500}{70}\times100=15000\)