Answer:
40% (see below)
Explanation:
First, make a ratio to simplify your situation:
Think about it like this:
If 25 is 100%, and the question is asking me for 10, which is x%, then what is x%?
Here's what I'm talking about:
10 x%
------ = --------
25 100%
Now, just cross multiply and simplify:
1000 = 25x
40 = x
x = 40
To check your answer, you can multiply 25 by 0.4 (the decimal form of 40%) to see if it worked because 40% of 25 is 10:
25 (0.4)
10