(12+52+92+…… upto 20 terms )+(3+7+11+...upto 20 terms)
$\begin{aligned}
& =\sum_{\mathrm{r}=1}^{20}(4 \mathrm{r}-3)^2+\sum_{\mathrm{r}=1}^{20}(4 \mathrm{r}-1) \
& =\sum_{\mathrm{r}=1}^{20}(4 \mathrm{r}-3)^2+(4 \mathrm{r}-1) \
& =4 \sum_{\mathrm{r}=1}^{20}\left(4 \mathrm{r}^2-5 \mathrm{r}+2\right) \
& =16 \sum_{\mathrm{r}=1}^{20} \mathrm{r}^2-20 \sum_{\mathrm{r}=1}^{20} \mathrm{r}+8 \sum_{\mathrm{r}=1}^{20} 1=41880
\end{aligned}$