If you wish to accumulate $100,000 in the child's college fund after 18 years, and you can invest at a 6% annual rate, how much must you invest at the end of each year if the first deposit is made at the end of the first year?

Well, what was the initial deposit made at the end of the first year?

And is this a homework question or are you really looking to start saving for your child's education?

You need $3,713.65 every year.
See Calculations for 18 years.

1 3,713.65
2 3,713.65 3,936.47
3 3,936.47 4,172.65
4 4,172.65 4,423.01
5 4,423.01 4,688.40
6 4,688.40 4,969.70
7 4,969.70 5,267.88
8 5,267.88 5,583.95
9 5,583.95 5,918.99
10 5,918.99 6,274.13
11 6,274.13 6,650.58
12 6,650.58 7,049.61
13 7,049.61 7,472.59
14 7,472.59 7,920.94
15 7,920.94 8,396.20
16 8,396.20 8,899.97
17 8,899.97 9,433.97
18 9,433.97 10,000.01

It's homework, most definitely.

Sara, have you made an attempt to solve this?