Jack and jill's place is a nonprofit nursery school run by the parents of the enrolled children. since the school is out of town, it has a well rather than a city water supply. lately, the well has become unreliable, and the school has had to bring in bottled drinking water. the school's governing board is considering drilling a new well (at the top of the hill, naturally). the board estimates that a new well would cost $3,150 and save the school $630 annually for 10 years. the school's hurdle rate is 8 percent.