Hey there!
For this problem, consider how many cards there are that fit the two descriptions you've been given, based on the fact that the numbers only go up to 25:
number less than 4 (not including 4): 1, 2, 3
multiple of 9: 9, 18
That's 5 cards total. That means that out of 25 cards, there are 5 you can pick that fit the description in your problem. You can find the exact probability by simply dividing the smaller number by the larger:
5 / 25 = 0.2, or 20%
If you wanted to check your final answer of 0.2 or 20%, you could just multiply 5 by however many parts your percentage is of 100, since percentages are always out of 100 (in this case, 20% is 1 of 5 parts of 100):
5 * 5 = 25
Hope this helped you out! :-)
