UR Safe Systems installs home security systems. Two of its systems, the ICU $100$ and the ICU $900,$ have these characteristics:

$\backslash$table$[[$Design Specifications,ICU $100,$ICU $900,$Cost Data$],[$Video cameras,$1,3,$$$\frac{150}{?}$ ea$],[$Video monitors,$1,1,$$$\frac{75}{e}a$