Which is bigger 0.45 or 2/5

The biggest out of the two possible answers is 0.45. 2/5 in decimal form is 0.4, or in percentage form becomes 40%. However, if 0.45 is changed into a fraction, it becomes 9/20 in its smallest form, which is difficult to compare. If we consider 0.45 as a percentage, however, it obviously becomes 45%, which is bigger than 40% so we can confirm that 0.45 is larger than 2/5.