30% of 48 is equal to 14.4. Since the sales team cannot sell .4 of a computer, this must be rounded. Even though a 14.4 would normally round down to 14, it must be rounded up to a fifteen because 14 is less than 30% of 48. This means that the sales team must sell 15 MORE computers this month than they did last month. Last month they sold 48 computers, so they should sell 48+15 computers, or 63 computers this month.