since it's per annum, we'll assume is compounded interest.
[tex]~~~~~~ \textit{Compound Interest Earned Amount} \\\\ A=P\left(1+\frac{r}{n}\right)^{nt} \quad \begin{cases} A=\textit{accumulated amount}\\ P=\textit{original amount deposited}\dotfill &\pounds 3550\\ r=rate\to 3.05\%\to \frac{3.05}{100}\dotfill &0.0305\\ n= \begin{array}{llll} \textit{times it compounds per year}\\ \textit{per annum, thus once} \end{array}\dotfill &1\\ t=years\dotfill &5 \end{cases} \\\\\\ A=3550\left(1+\frac{0.0305}{1}\right)^{1\cdot 5}\implies A=3550(1.0305)^5\implies A\approx 4125.42[/tex]
