John invested Rs. (P-4000) and Rs. (P+5000) in scheme A and scheme B respectively. The rate of interest in scheme A and B is (R+1)% and (R-1)% respectively and each of the schemes is on simple interest. After eight years, the interest obtained from scheme B is Rs. 2880 more than that of scheme A. If Rs. 44000 was invested in scheme C at the rate of (R+2)% per annum on simple interest then an amount Rs. 39600 will be obtained as an interest after 6 years, then what is the value of ‘P’?

Solution

If Rs. 44000 was invested in scheme C at the rate of (R+2)% per annum on simple interest then an amount Rs. 39600 will be obtained as an interest after 6 years. 44000x(R+2)%x6 = 39600 [44000x(R+2)x6]/100 = 39600 [440x(R+2)x6] = 39600 2640x(R+2) = 39600 (R+2) = 15 R = 15-2 R = 13 John invested Rs. (P-4000) and Rs. (P+5000) in scheme A and scheme B respectively. The rate of interest in scheme A and B is (R+1)% and (R-1)% respectively and each of the schemes is on simple interest. After eight years, the interest obtained from scheme B is Rs. 2880 more than that of scheme A. (P-4000)x(R+1)%x8 + 2880 = (P+5000)x(R-1)%x8 Put the value of ‘R’ in the above given equation. (P-4000)x(13+1)%x8 + 2880 = (P+5000)x(13-1)%x8 (P-4000)x14%x8 + 2880 = (P+5000)x12%x8 [(P-4000)x14x8]/100 + 2880 = [(P+5000)x12x8]/100 [(P-4000)x112]/100 + 2880 = [(P+5000)x96]/100 [(P-4000)x112] + 288000 = [(P+5000)x96] 112P-448000+288000 = 96P+480000 112P-96P-160000 = 480000 16P = 480000+160000 16P = 640000 Value of ‘P’ = 40000