Percentage question

Question

There are two candidates p and q in an election. During the campaign,40% of the voters promised to vote for P ,and rest for Q. However, on the day of election 15% of the voter went back on their promise to vote for P and instead voted for Q. 25% of the voters went back on their promise to vote for Q and instead voted for P. Suppose P lost by two votes, then what was the total no. of voters?

Answer 1

let total voters=x
promised voter for P & Q are 0.4x and 0.6x respectively.
15% of P back on their promise and voted Q i.e 0.06x less in P but that no. of voters will increase in Q.25% of Q back on promise and voted P i.e 0.15x less in Q but increase in P.
i.e votes of P=0.4x-0.06x+0.15x=0.49x
votes of Q=0.6x+0.06x-0.15x=0.51x
0.49x+2=0.51x
so x=100.