Respuesta :
The simple interest formula is:
A = P · (1 + r · t)
where:
A = total amount
P = principal
r = rate
t = time
Let's solve for r:
A = P + P · r · t
P · r · t = A - P
r = (A - P) / (P · t)
The quantity A - P is defined as the Interest, therefore:
r = I / (P · t)
= 1020 / (8500 · 4)
= 0.03
Therefore the rate was 3%.
A = P · (1 + r · t)
where:
A = total amount
P = principal
r = rate
t = time
Let's solve for r:
A = P + P · r · t
P · r · t = A - P
r = (A - P) / (P · t)
The quantity A - P is defined as the Interest, therefore:
r = I / (P · t)
= 1020 / (8500 · 4)
= 0.03
Therefore the rate was 3%.