Which promise of Devi Lal draw in election campaign to attracted the people?

2/5 of the voters promise to vote for Mulayam Singh and rest promise to vote Mayawati. On election day 15% of the voters went back on their promise to vote for Mulayam Singh & 25% of thevoters went back on their promise to vote for Mayawati. Mayawati won by 1500 votes. Find the total number of voters.