So,
In order to simplify a fraction, we have to factor both the numerator and the denominator.

Cross out ones.
There are 12 months in most years.
.. 23%/12 ≈ 1.91667%
_____
The answer shown in your picture is correct to 2 decimal places.
The original answer should be 48/100.
Reduced is 24/50
Even more is 12/25
Your answer is 12/25
You should divide 280 into 3 which would equal 9