Find the simple interest earned on Rs.20000 for 2 years at 10% p.a.
Rs.4500
Rs.2000
Rs.4000
Rs.6000
$\begin{aligned} & \text { S.I }=(2000 \times 2 \times 10) / 100=4000 \\ & \text { Or S.I }=\text { RT } \% \text { of } P=10 \times 2 \% \mathrm{P} \text { of P i.e } 20 \% \text { of } \\ & =20 / 100 \times 20000=4000 .\end{aligned}$