Answer:
4.3%
Step-by-step explanation:
Write out the formula for simple interest:
i = p r t, where i is the interest earned, p is the principal, r is the interest rate as a decimal fraction, and t is the elapsed time in years.
Here, this i = p r t becomes
$645 = $3000*r*(5 yr).
This is equivalent to:
$645 = $15000r.
Solving for r by dividing both sides of this equation by $15000, we get
$645
r = ------------ = 0.043
$15000
Thus, the correct answer is the first one: 4.3%
