Answer :
[tex]\begin{gathered} Let\text{ Annual interest rate be represented by: R} \\ \text{from I = }\frac{\text{PRT}}{100} \\ I\text{ = \$30} \\ P\text{ = \$500} \\ R\text{ = ?} \\ \text{T = 1} \\ \\ R\text{ = }\frac{100I}{PT}\text{ = }\frac{100\text{ }\times30}{500\times1}\text{ = }\frac{3000}{500}\text{ = }\frac{3000}{500}\text{ = 6}^{}\text{\%} \end{gathered}[/tex]