A sum is invested at simple interest. If the rate of interest is 20% per annum, then in how much time will it become double of itself?

10 years 8 years 4 years 5 years

5 years

Let initial sum = P Required amount = 2P Simple interest = 2P - P = P We know , Simple Interest = \(\frac{Principal ×Rate × Time }{100}\) P = \(\frac{P× 20 × Time }{100}\) Time = 5  years