One possible expression using the numbers 3, 25, 15, and 5 that results in a value of 225 is:

$(15 \times 15) = 225$

Here's the breakdown:

• $15 \times 15 = 225$ (Since $15 \times 15 = 225$)

Thus, the expression $15 \times 15$ simplifies to 225.

Would you like further details or have any questions?

Here are some related questions to explore:

1. What other expressions involving these numbers might also result in 225?
2. How could you use division instead of multiplication to achieve the same result?
3. Can you create a more complex expression using all four numbers?
4. How would the expression change if you included addition or subtraction?
5. What is the square root of 225?

Tip: When dealing with specific numbers, think of operations such as multiplication or squaring first to reach larger target values.