Given Data:
The initial investment is: p=$21
The simple intrest rate is: r=5%
The total time piriod is: t=4 years.
The expression to calculate the intrest in t years is,
[tex]\begin{gathered} i=P\times\frac{r}{100}\times t \\ i=21\times\frac{5}{100}\times4 \\ i=20\times\frac{1}{20} \\ i=1 \end{gathered}[/tex]Thus, the total intrest after 4 years is $1.
The expression to calculate the final balance after 4 years is,
[tex]\begin{gathered} FINAL\text{ BALANCE= P+i} \\ =21+1 \\ =22 \end{gathered}[/tex]Thus, the final balance after 4 years will be $22.
