Two friends P & Q started a business investing amounts in the ratio of 5: 6. R joined them after seven months investing an amount equal to that of Q's amount. At the end of the year 23% profit was earned which was equal to Rs. 98,578. What was the approximate amount invested by R? 1. Rs. 75,460 2. Rs. 79,370 3. Rs. 75, 000 4. Data inadequate 5. None of these