$\backslash$table$[[$Cell$,$Name,$\backslash$table$[[$Final$],[$Value$]],\backslash$table$[[$Reduced$],[$Cost$]],\backslash$table$[[$Objective$],[$Coefficient$]],\backslash$table$[[$Allowable$],[$Increase$]],\backslash$table$[[$AI$],[$Di$]]],[$$$B$$$6,$Activity $1,3,0,30,23,],[$$$C$$$6,$Activity $2,6,0,40,50,],[$$$D$$$6,$Activity $3,0,-7,20,7,1]]$

Constraints

$\backslash$table$[[,,$Final,Shadow,Constraint,Allowable,Al$],[$Cell$,$Name,Value,Price,R$.$H$.$ Side,Increase,Di$],[$$E$$2,$Resource A$,20,7\mathrm{.}78,20,10,],[$$$E$$$3,$Resource B$,30,6,30,50,],[$$E$$4,$Resource C$,18,0,40,1E+30,]]$

What is the allowable range for the right$-$hand$-$side for Resource $C?$

$$ a$)18RH{S}_r$