Here R2,R3,R4 are in parallel $\begin{aligned}
& \frac{1}{\mathrm{R}{234}}=\frac{1}{\mathrm{R}2}+\frac{1}{\mathrm{R}3}+\frac{1}{\mathrm{R}4} \
& \mathrm{R}{234}=2 \Omega
\end{aligned}R{234}isinserieswithR_1so\begin{aligned}
& \mathrm{R}{\mathrm{eq}}=\mathrm{R}{234}+\mathrm{R}_1=2+10=12 \Omega \
& \mathrm{i}=\frac{12}{12}=1 \mathrm{Amp}
\end{aligned}$
