\(n_{CaO}=\dfrac{560}{56}=10\left(kmol\right)\)
\(CaCO_3\xrightarrow[]{t^o}CaO+CO_2\)
\(n_{CaCO3}=n_{CaO}=10\left(kmol\right)\Rightarrow m_{CaCO3\left(lt\right)}=10.100=1000\left(g\right)\)
\(\Rightarrow m_{CaCO3\left(tt\right)}=\dfrac{1000}{80\%}=1250\left(kg\right)\)