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Brian invests £6500 into his bank account.
He receives 4% per year compound interest.
How many years will it take for Brian to have more than £10000?

Respuesta :

Answer:

approximately 11 years

Step-by-step explanation:

Use the compound interest formula:

A = P(1+r)^n, where r is the annual interest rate as a decimal fraction and t is the number of years.

Here we have:

(10000 pounds) = (6500 pounds)(1 + 0.04)^t and must find the value of t.

Solve for (1.04)^t by dividing both sides of this equation by (6500 pounds):

1.5385 = 1.04^t

Take the log of both sides:

log 1.5385 = t*log 1.04, or

       log 1.5385

t = --------------------  = (0.1871)/0.0170  =  10.98, or approximately 11 years

         log 1.04