The formula for the present value (PV) of a perpetuity is given by:
PV = \(\frac{C}{r}\),
where C is the periodic payment and r is the interest rate per period. Here, PV = 40,000 and C = 5,000.
Substituting these values:
40,000 = \(\frac{5,000}{r}\).
Simplify to find r:
r = \(\frac{5,000}{40,000}\) = 0.125 (per 6 months).
Since r = 0.125 is the rate for 6 months, the annual rate is:
rannual = 0.125 × 2 = 0.25 = 25%.
Thus, the correct answer is 25%.