Abby is a Lego fan. Recently, she finds a Superset that she would like to work with, but the cost of the Superset is $150. Since she owns 4 sets (Sets 1-4), she would like to see whether there is a cheaper way to assemble the Superset by combining other sets. The price of the sets are given in Row 38.

a) Formulate the problem to see how much it would cost to assemble the Superset from the other sets. Which is cheaper, buying the Superset, or buying additional sets?(Hint: Sets 1 - 4 would incur no additional costs since she owns them.)

b) If Abby could borrow Sets 11-12 (only 1 of each) from her friends, should she buy the Superset or purchase the other sets instead? What would be the cost of buying the sets now?