In an election involving two candidates, 86 votes were declared invalid. The winning candidate secured 58% and won by 256 votes. The total number of votes polled is:

Correct option is C

GIVEN:
Number of votes declared invalid = 86
Percentage of votes of winning candidate = 58%
Number of votes by which winning candidate wins by = 256 votes
Solution:
Let T represent the total number of votes polled.
The winning candidate received 58% of the valid votes and won by a margin of 256 votes.
86 votes were declared invalid.
we know that:
Valid votes = T-86
Votes for the winning candidate = 58% of valid votes = 0.58×(T-86)
Votes for the losing candidate = 42% of valid votes = 0.42×(T-86)
winning candidate won by 256 votes
0.58×(T-86)-0.42×(T-86)=256
0.16×(T-86)=256
T-86=256/0.16
T - 86 = 1600
T=1686