The interes is 5%
The initial capital is 3840.
The ending capital is 4800.
If it is only simple interest, we can calculate this as:
[tex]\begin{gathered} C_f=C_0+n\cdot i\cdot C_0 \\ n=\frac{C_f-C_0}{i\cdot C_0}=\frac{4800-3840}{0.05\cdot3840}=\frac{960}{192}=5 \end{gathered}[/tex]Exactly 5 years, if the interest is not compound.
