If we're talking about simple interest (and not compound interest), then
i = P*r*t
i = 5000*0.03*1
i = 150
$150 in simple interest is earned for the year
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notes:
- P = principal = amount invested or deposited = 5000
- r = 0.03 is the decimal form of 3%
- t = number of years that pass by = 1