Answer:
answer b (0.73)
Explanation:
"Triple" means to increase in size by a factor of 3.
Thus, B = (1 + r)^2 becomes
3 = (1 + r)^2. Our task is to determine the value of r, the annual interest rate.
Taking the square root of both sides, we get
√3 = 1 + r, which yields √3 - 1 = r.
This is approx. 1.732 - 1.000, or 0.732. Answer b) is closest.