Answer: it will take 17.5 years to double his money in the account.
Explanation:
We would apply the formula for determining compound interest which is expressed as
A = P(1+r/n)^nt
Where
A = total amount in the account at the end of t years
r represents the interest rate.
n represents the periodic interval at which it was compounded.
P represents the principal or initial amount deposited
From the information given,
P = $500
A = 500 × 2 = $1000
r = 4% = 4/100 = 0.04
n = 4 because it was compounded 3 times in a year.
Therefore,.
1000 = 500(1 + 0.04/4)^4 × t
1000/500 = (1 + 0.01)^4t
2 = (1.01)^4t
Taking log of both sides, it becomes
Log2 = 4tlog 1.01
0.301 = 4t × 0.0043 = 0.0172t
t = 0.301/0.0172
t = 17.5 years