4. A computer user plans to purchase single-piece software and boxed disks, priced at 60 yuan and 70 yuan each, respectively, with a budget of no more than 500 yuan. According to the needs, the user must buy at least 3 pieces of software and at least 2 boxes of disks. How many different purchasing options are there?
4. First buy 3 pieces of software and 2 boxes of disks. With the remaining 180 yuan, if you do not buy software, you can buy 0, 1, or 2 more boxes of disks; if you buy 1 more piece of software, you can buy 0 or 1 more box of disks; if you buy 2 more pieces of software, you cannot buy any more disks; if you buy 3 more pieces of software, you also cannot buy any more disks. There are 7 ways to make the purchase.