In an election between two candidates, the winning candidate got 70% of the valid votes and won by a majority of 9000 votes. If out of total votes polled 90% votes are valid, then what is the total number of votes polled?
A sum of Rs 4000 becomes Rs 7000 in 6 years at simple interest. If the rate of interest becomes double of itself, then what will be the amount (in Rs) after 6 years?