A village moneylender is willing to make a cropping season loan as long as she can earn a 15% margin on the deal. A farmer needs $50 to buy fertilizer. If the farmer buys the fertilizer, her prot at the end of the cropping season will be as follows: 25% chance: $150 profit 25% chance: $100 prot 25% chance: $50 prot 25% chance: $0 prot You can assume the moneylender is the first person to be repaid by the farmer (i.e. the farmer cannot hide prots from the moneylender). What is the lowest interest rate that the money lender will offer