Question

in an election between two candidates 10% of the voters did not cast their vote. 10% of the votes polled were found invalid. the successful candidate got 54 % of the valid votes and won by a majority of 1620 votes. find the number of voters enrolled on the voters list.

Answer 1

for the successful candidate
let x be the total votes cast
1620=x-54x/100
1620={100x-54x}/100
1620=46x/100
x=1620.100/46
x=3521.73
or by rounding it off
x=3522

since 20 percent of the votes were not valid  or not cast 
therefore,
let the total number of people on the voters' list be y
x+20%y=y
3522+20y/100=y
3522=y-20y/100
3522=100y-20y/100
3522=80y/100
y=3522.100/80
y=4402.5
or by rounding it off
y=4403
therefore the total number of people on the voters' list are 4403.

Hope that helps!!!