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