Question

Brian invests £8000 into his bank account.
He receives 3% per year compound interest.
How many years will it take for Brian to have more than £9500?

Answer 1

Given :

Future Amount = £9,500

Principal amount = £8,000

Rate of interest = 3%

To Find :

Time period in years.

Solution :

Formula for compound interest

$A=P(1+\frac{R}{100})^t$

A = Future amount = £9500

P = Principal amount = £8000

R = 3% = $\frac{3}{100}$

Let the time of investment represents by t.

$9500=8000(1+\frac{3}{100})^t$

$9500 = 8000(1+0.03)^t$

$9500 = 8000(1.03)^t$     [divide both sides by 8000]

$1.03^t=\frac{19}{16}$

$log(1.03^t)=log(\frac{19}{16})$

$t=\frac{log(\frac{19}{16}) }{log(1.03)}$

t = 5.813844 ≈ 5.814 years

It will take more than 5.814 years for Brian to have more than  £9500.

Answer 2

Answer:

Basically six years when you round 5.814

Step-by-step explanation: