Mathematics · Simple Interest

Ram on his birthday received Rs. 8,500 as a gift from his relatives. To encourage Ram towards saving money, his grandfather asked him to lend his money to him at 20% simple interest per annum. Ram's father proposed to borrow money from Ram at 15% simple interest per annum. His elder brother is also interested to borrow any amount of money from Ram at 10% simple interest per annum. But his grandfather is interested to take only Rs. 5,000 and his father is interested to take the entire money but not any part of it. If Ram lent all the gifted amount, then by his next birthday the maximum possible total amount (principal + interest) he gets is: