The new account balance at the end of 2 years is $517.
Simple interest
5 yearsUsing this formula I= (P+r×t)
Where: I=Interest=?
P=Principal=$400
r=Interest rate=3.5%
t=Time=5 years
Hence: I= ($400×0.035 x 5) which makes I= $70
2 years
I=Interest=?
P=Principal=$470
r=Interest rate=5%
t=Time=2 years
I=($470+0.05×2) which makes I=$47
New balance:
New balance=$400+$70+$47
New balance=$517
Inconclusion the new account balance at the end of 2 years is $517.