A sum of money, when invested at the rate of 6.25% simple interest per annum, amounts to  \(\frac{11 }{8 }\) times of itself in 'n' years. What is the value of 'n' ?

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Let principal = P & Amount = \(\frac{11 }{8 }\)P

Amount = Principal + Simple interest

\(\frac{11 }{8 }\)P = P + Simple interest 

Simple Interest = \(\frac{11 }{8 }\)P - P = \(\frac{3 }{8 }\)P

We know ,

Simple Interest = \(\frac{Principal ×Rate × Time }{100}\)

Time = ' n ' years

\(\frac{3 }{8 }\)P = \(\frac{P × 6.25 × n }{100}\)

\(\frac{3 }{8 }\) = \(\frac{ 6.25 × n }{100}\)

n = 6 years