We know that plant only utilised $1-2\;\%$ of total energy incident on earth. In the given dustion $100000 \mathrm{Kcal} / \mathrm{m}^{2} / y r$ salar radiation is incident on earth. So plant producer utilize $1\; \%$ of $100000 \mathrm{kcalm}^{2} / \mathrm{yr}$ and that $1\; \%$ is$ \frac{100000 \times 1}{100}=1000\; \mathrm{kcal} / \mathrm{m}^{2} / y r$And from produces to the next level only $10 \%$ will goes, so$\frac{1000 \times 10}{100}=100\; \mathrm{kcal} / \mathrm{m}^{2} / \mathrm{yr}$ will be transferred to primary consumer which is called secondary production