The following formula is applicable;
A=P(1+r)^n
Where,
A = Total amount accrued after 10 years (this is the amount from which the yearly withdrawals will be made from for the 30 years after retirement)
P=Amount invested today
r= Annual compound interest for the 10 years before retirement
n= Number of years the investments will be made.
Therefore,
A= Yearly withdrawals*30 years = $25,000*30 = $750,000
r= 9% = 0.09
n= 10 years
P= A/{(1+r)^n} = 750,000/{(1+0.09)^10} = $316,808.11
Therefore, he should invest $316,808.11 today.
