Given:
tuition: 180,000 per year
period to save: 18 years
annual rate of return : 6%
FV = PV * (1+r)^t
180,000 = PV * (1 + 0.06)¹⁸
180,000 = PV * (1.06)¹⁸
PV = 180,000 / (1.06)¹⁸ = 180,000 / 2.854 = 63,069.38
Jack and Jill will have to invest 63,069.38 in the first year to have a total of 180,000 after 18 years.
Using Future Value Annuity formula:
FV of Annuity = P [{(1+r)^n - 1} / r]
180,000 = P [{(1.06)¹⁸ - 1} / 0.06]
180,000 = P (30.906)
P = 180,000 / 30.906
P = 5,824.11
Jack and Jill will have to deposit 5,824.11 every end of the year for the total to reach 180,000 after 18 years.