We have the next formula to the simple interest
[tex]I=P\times r\times t[/tex]where
I= interest earn after t years
P is the initial deposit
r is the rate
t is the time
P=1500
r=2.5%
t= 4 years
then we substitute the values in the formula
[tex]I=1500(.025)(4)[/tex][tex]I=150[/tex]He will earn $150 after 4 years, his final capital will be $1650