Answer:
Step-by-step explanation:
The compound interest formula is expressed as;
A = P(1+r/n)^nt
r is the rate
n is the time of compounding
t is the time in years
Given
P = 20,000
r = 6.5% = 0.065
t = 4
n = 1/12
Substitute
A = 20000(1+0.065(12))^40(1/12)
A = 2000(1+0.78)^3.33
A = 20000(1.78)^3.33
A = 20000(6.8218)
A = 136,435.88
Hence $he will have approximately 136,436 in his account after 40years compounded monthly
