Dakota earned $15.75 in interest in Account A and $28.00 in Account B after 21 months. If the simple interest rate is 3.0 for Account A 4.0% for Account B, which account had the greater principal? Explain

account B had the greater capital.
Step-by-step explanation:
The formula for determining simple interest is expressed as
I = PRT/100
Where
I represents interest paid on the amount deposited.
P represents the principal or amount deposited
R represents interest rate
T represents the duration in years.
Considering account A,
I = $15.75
T = 21 months = 21/12 = 1.75 years
R = 3%
Therefore,
15.75 = (P × 3 × 1.75)/100
15.75 = 0.0525P
P = 15.75/0.0525
P = 300
Considering account B,
I = $28
T = 21 months = 21/12 = 1.75 years
R = 4%
Therefore,
28 = (P × 4 × 1.75)/100
28 = 0.07P
P = 28/0.07
P = $400
Therefore, account B had the greater capital.

Account b had greater