question_answer 56)

In a bank, principal increases at the rate of r% per year. Find the value of r is Rs.100 double itself in 10 years (loge 2 = 0.6931) 

Answer:

Let P0 be the initial principal and the principal after t years be Pt       Given principal P0 = Rs.100       Rate of  interest = r%; time, t = 10 years       Amount, P10 = Rs.200       According to question                   Integrating both sides.                           ? (1)       When t = 0, P = P0 = Rs.100        log 100 = 0 + C                   Also, when t = 10, P = Rs.200.