If 15000 Rs. is lent at (x + 2)% rate of interest for 'x' years in scheme 'A' and 18000 Rs.is lent at (x + 6)% rate of interest for (x + 1) years in scheme 'B' then the difference between the simple interest received from both schemes is 3120 Rs. Find the sum invested in another scheme 'C' if the sum is invested at '6x'% rate of compound interest per annum for 1 year 4 months and the total amount received from scheme 'C' is 14560 Rs.?