Answer:

Step-by-step explanation:
Write down the problem;

Simplify

Convert so that the fractions have a common denominator; multiply the numerator and denominator of both fractions such that the denominators are equal;

Add the fractions;

Convert to mixed number;

Answer:
3.2%
Step-by-step explanation:
The computation of the annual rate of interest is shown below:
As we know that
Simple interest = Principal × rate of interest × time period
($1,857.60 - $1,800) = $1,800 × rate of interest × 1
$57.60 = $1,800 × rate of interest × 1
So, the rate of interest is
= $57.60 ÷ $1,800 × 100
= 3.2%
Hence, the rate of interest on annual basis is 3.2%