Explanation

To calculate simple interest, we use the formula:

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

Where:

Principal (P) = Rs. 5640

Rate (R) = 6% per annum = 6/100 = 0.06

Time (T) = 7 months = 7/12 (since there are 12 months in a year)

Plugging in the values, we get:

SI = (5640 x 0.06 x 7/12)

= (5640 x 0.06 x 0.5833)

= 199.60

So, the simple interest is Rs. 199.60!