Ming has a budget of $60/month to spend on high-tech at-home entertainment. There are only two goods that he considers: CD's and video rentals. For each of the situations described below, draw Ming's budget constraint with CDs/month on the x-axis and video rentals/month (not cards/month) on the y-axis.

5) CD's cost $12 each and video rentals are $4 each. However, for $24 Ming can purchase a video card that allows him to rent 10 videos in a month; for more than 10 videos, the cost returns to $4 each. He is allowed to purchase only one of these cards per month.

6) As in part "5," but now Ming is allowed to purchase as many of these cards as he would like each month (but he must use the cards entirely on each month.)

I need help with 6 please!