Respuesta :

5000(1+.085/4)^n=1000
to find n use log:
1.02125^n 
N X log1.02125
when computed=32.9
round to 33 quarters compounded
33/4
equals to 8 years 3 months

Oh this is easy
5,000x.085=425
That is the amount he made in the year from intrest
Now cut that into a 4th
106.25
He makes 106.25 quarterly