Given:
Principal P = 5300 rupees.
Annual rate of interest r = 6.5% = 0.065.
Total amount A = 6678 rupees.
Consider the formula to get the amount by simple interest.

Substitute P =5300, r= 0.065 and A=6678 in the formula, we get

Dividing both sides by 5300, we get


Subtracting 1 from both sides of the equation, we get


Dividing both sides by 0.065, we get



Hence the period = 4 years.