A businessman invests an equal sum in Scheme A and Scheme
B. Scheme A gives simple interest at 25% per annum for 4 years. Scheme B gives compound interest at double the rate for half the time period. If the difference between the interests from the two schemes is Rs. 2500, find the total amount invested.

ATQ, Let the amount invested in each scheme be Rs. 100. Scheme A gives simple interest at 25% per annum for 4 years. Interest from Scheme A = 100 × 25 × 4/100 = Rs. 100 Scheme B gives compound interest at double the rate for half the time. Rate for Scheme B = 50% Time for Scheme B = 2 years Amount from Scheme B = 100 × 150/100 × 150/100 Amount from Scheme B = 225 Interest from Scheme B = 225 − 100 = Rs. 125 Difference between the interests per Rs. 100 = 125 − 100 = Rs. 25 When difference is Rs. 25, amount invested in each scheme = Rs. 100 When difference is Rs. 2500, amount invested in each scheme = 2500 × 100/25 = Rs. 10000 Total amount invested = 10000 + 10000 = Rs. 20000