Additional problem:

After buying a computer system, Sim Thomas must decide whether to purchase $(1)$ a complete maintenance $($or service$)$ policy at a cost of $$500,$ which would cover all maintenance costs; $(2)$ a partial maintenance policy at a cost of $$300,$ which would cover some of the costs of maintenance; or $(3)$ no maintenance policy. The consequences, costs and probabilities are given in the following table:

$\backslash$table$[[,\backslash$table$[[$MAINTENANCE$],[$REQUIRED$]],\backslash$table$[[$MAINTENANCE$],[$NOT REQUIRED$]]],[$No Service Agreement,$$3,000,$$$0)($PLEASE ANSWER PARTS A AND B$!!!)$