To find the rate of simple interest, we can use the formula:

Simple Interest (SI) = (Principal * Rate * Time) / 100

We are given two different scenarios:

1. The money amounts to Tk. 5600 in 2 years.
2. The money amounts to Tk. 6500 in 5 years.

Let's use the first scenario to calculate the rate:

SI = (Principal * Rate * Time) / 100

5600 = (Principal * Rate * 2) / 100

Now, rearrange the formula to solve for the rate (R):

Rate (R) = (SI * 100) / (Principal * Time)

Rate (R) = (5600 * 100) / (Principal * 2)

Now, let's use the second scenario to calculate the rate:

SI = (Principal * Rate * Time) / 100

6500 = (Principal * Rate * 5) / 100

Again, rearrange the formula to solve for the rate (R):

Rate (R) = (SI * 100) / (Principal * Time)

Rate (R) = (6500 * 100) / (Principal * 5)

Now, let's compare the rates from both scenarios:

Rate in the first scenario (R1) = (5600 * 100) / (Principal * 2) Rate in the second scenario (R2) = (6500 * 100) / (Principal * 5)

Since both scenarios involve the same principal amount, we can compare the rates:

R1 / R2 = [(5600 * 100) / (Principal * 2)] / [(6500 * 100) / (Principal * 5)]

R1 / R2 = (5600 * 100 * 5) / (6500 * 100 * 2)

R1 / R2 = 28000 / 13000

R1 / R2 = 2.1538 (approximately)

So, the rate of interest is approximately 2.1538 times higher in the second scenario compared to the first scenario.

Now, let's calculate the rate in the second scenario (R2):

R2 = (Rate in the first scenario, R1) * 2.1538

R2 ≈ 6% (approximately)

Therefore, the rate of interest is approximately 6%.