The solution says Qty. A is greater since x should be 5/6/7/8/9. However, since the digit after x is 9, couldn’t x=4 also work? Wouldn’t 12.1549 be rounded to 12.155 which, then rounded to the hundredths place, would be 12.16? Please let me know if I am missing something.
Thanks in advance!

Thanks for the explanation!
So if I understand right, we only check whether the digit to the immediate right (of the place we want to round to) is 5 or more and round off in one step?