Question

If ​$450 is invested for one year at 12.1​%simple​ interest, how much interest is​ earned?

Answer 1

I = p * r * t
p = 450
i = interest ??? That's what you are trying to find.
r = 12.1/100 = 0.121
t = 1 year

i = 450 * 0.121 * 1
i = 54.45 dollars.