Answer:
$1,100 at 3.2% for 3 years -> $105.60
$990 at 3.15% for 4 years -> $124.74
$1,025 at 2.8% for 5 years -> $143.5
Step-by-step explanation:
Simple interest formula is:
A = P*(1 + r*t)
where A if final account, P is principal, r is annual interest rate (as decimal) and t is time in years
Interest earned is A - P, then:
I = P*(1 + r*t) - P = P(1 + r*t - 1) = P*r*t
If P = $1100, r = 0.032 and t = 3, then:
I = 1100*0.032*3 = $105.6
If P = $990, r = 0.0315 and t = 4, then:
I = 990*0.0315*4 = $124.74
If P = $1025, r = 0.028 and t = 5, then:
I = 1025*0.028*5 = $143.5
