You have $60 income per week to spend to spend on coffee and ice cream. A cup of coffee costs $4 and an ice cream costs $2. Your friend gives you a $20 gift certificate that can be used for ice cream cones (but not coffee.)
Graph your budget constraint for ice cream cones (horizontal axis) and coffee (vertical axis) with and without the $20 gift card.
The gift card makes you better (higher indifference curve) but you would prefer even more the $20 in cash (instead of the gift card). Illustrate this on your graph.
You now develop an allergy to ice cream and cannot eat it. Show your indifference curves between coffee and ice cream as well as the utility-maximizing choice of ice cream cones and coffee with the gift card. Also, show the utility-maximizing choices if given $20 cash instead of the gift card.