You are asked to find the value of the expression $\#(\#(2,0), 1)$, where $\mathrm{a}=\#(2,0)$ and $\mathrm{b}=1$.

According to the definition of the operation, $\#(\#(2,0), 1)=\#(2,0) \cdot \#(2,0)+1)$.

To calculate the value of the above expression, first calculate $\#(2,0)$.

According to the definition of the operation, $\#(2,0)=2 \cdot(2+0)=4$.

Substitute the value you have obtained for $\#(2,0)$ into the original expression and you will obtain $\#(\#(2,0), 1)=\#(4,1)$.

According to the definition of the operation, $\#(4,1)=4 \cdot(4+1)=20$.