Simple interest on a sum of money will be Rs 225 after three years. In the next 5 years amount becomes 3 times the principle. What will be the amount in eight years ?

To solve this problem, we need to use the formula for simple interest which is I = PRT/100, where I is the interest, P is the principal amount, R is the rate of interest, and T is the time.

Step 1: From the problem, we know that the simple interest after three years is Rs 225. So, we can write the equation as 225 = PR3/100.

Step 2: The problem also states that in the next 5 years, the amount becomes 3 times the principal. This means that the principal plus the interest for 5 years is equal to 3 times the principal. We can write this equation as P + PR5/100 = 3P.

Step 3: Now we have two equations and two unknowns (P and R), which we can solve simultaneously.

Step 4: Solving these equations, we get P = Rs 1500 and R = 5%.

Step 5: Now that we know the principal and the rate, we can find the amount after eight years. The amount is the sum of the principal and the interest for 8 years. So, A = P + PR8/100 = 1500 + 150058/100 = Rs 3000.

So, the amount after eight years will be Rs 3000.