Question

a bank account pays 5.5% annual interest compounded monthly how long will it take the money to be double in this account?​

Answer 1

Answer:

0.023

Explanation:

2p=p(1+r÷100)n

2=(1+5.5÷100)n

log2=nlog(1+5.5÷100)

0.023

Answer 2

6.4425 years

Explanation:

let principal be ₹100

amount after double = ₹ 200

compound interest = ₹ 100

interest rate = 5.5 %

i = R/(100*12) (compounded monthly)

 = 5.5/(100*12)

= 0.0045

total amount = P + ( 1 + i )n    ( n = no. of conversion periods in months )

              200 = 100 + ( 1 + 0.0045)

                  2 = ( 1.0045 )n

                  n = log 2 / log 1.0045

                  n = 77.31 months

time taken to double the money in years = 77.31/ 12

                                                                     = 6.4425 years