Brian invests £4000 into his bank account. He receives 7% per year compound interest. How many years will it take for Brian to have more than £8000?
11 years give or take
FV ==PV x [1 + R]^N
8000 ==4000 x [1 + 0.07]^N, solve for N
8000 ==4000 x 1.07^N
8000/4000 ==1.07^N
2 == 1.07^N
N ==Log(2) / log(1.07)
N ==10.245 - years to double your 4000 to 8000 pounds.
To get MORE than 8000 pounds, you will need about 10 years and ~4 months.
