Answer:
The amount he must invest is $93200
Step-by-step explanation:
We are given
Amount is $400000
A=400000
interest rate is 6%
r=0.06
t=80-55=25 years
P is amount to be invested
we can use formula
[tex]A=P(1+r)^t[/tex]
now, we can plug values
[tex]400000=P(1+0.06)^{25}[/tex]
[tex]P=93199.452[/tex]
[tex]P=93200[/tex]