We have to form 3-digit numbers using the given digits viz., 4, 2 and 5.
Note that if the repetition constraint is not mentioned in the question, we will consider that repetition is allowed.
So, using 4, 2 and 5, we can write the followinng 3-digit numbers:
222, 444, 555, 245, 254, 425, 452, 524, 542.
Therefore, 9 three digit numbers can bbe formed using the digits 2,4 and 5.
Now by arranging these numbers in ascending order, we get:
222 < 245 < 254 < 425 < 444 < 452 < 524 < 542 < 555