There are many parts to this question so I will just talk about it for a bit.
The interet rate stays set at 5% pa compounded monthly.
this is 0.05/12 = 0.00416666666666
You need to work out how much money you will need in the accout on Suzie's 18 birtday., there are 2 parts to this.
1) Suzzie will need $1000 at the beginning of each month for 4 years and you need to know how much this equates to on her 18th birthday.
You can do this as the present value of an annuity due problem.
r=0.00416666666666
n=48
M=1000
2) You also need to work out what $30000 at the beginning of each year for 4 years equates to.
Before you can do this you need to work out what the effective interest rate of 0.00416666666666 per month is per year.
Solve this to get the answer. 1.00416666666666^12=1+R
Then
Use the present value of an annuity due formula using this new R, n=4, M=30000.
I'll call this total A18
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3) Add those answers together and you will know how much money you need by the 18th birthday.
4) Gran deposits X amount of dollars at the beginnig of every month for 12*18= 216 months
and at the end of it her Future value of an annuity due total will be equal to A18
Maybe you can use this outline to work the answer out for yourself.
Good luck :)
