Answer:
The correct option is C. 18 years
Step-by-step explanation:
Principal = $1900
Rate of interest, r = 4%
The interest is compounded semi annually ⇒ n = 2
Amount = $3875.79
We need to find the time for which the money was in the account.
[tex]Amount = Principal\times (1+\frac{rate}{n\times 100})^{n\times time}\\\\\implies 3875.79=1900\times (1+\frac{4}{100\times 2})^{2\times time}\\\\\implies \frac{3875.79}{1900}=(1.02)^{2\times time}\\\\\implies 2.04 = (1.02)^{2\times time}\\\\\implies 2\times time = 36\\\\\implies time = 18[/tex]
Hence, The money was in the account for 18 years
Therefore, The correct option is C. 18 years
