Ajay and Vijay jointly invest an amount 'x' in a simple interest scheme for 4 years. Ajay contributes 40% of 'x' at an interest rate of 7% per annum, while Vijay invests the remaining 60% of 'x' at 9% per annum. The total simple interest earned by both Ajay and Vijay together is Rs. 13,120. What is the value of 'x'?