1. The problem appears to involve simplifying or evaluating the expression with numbers 5, 3, 3, and 25. 2. Since the input is unclear, let's assume the problem is to multiply 5 by 3, then multiply the result by 3, and finally multiply by 25. 3. The formula for multiplication of numbers is simply $a \times b = c$. 4. Calculate step-by-step: 1) $5 \times 3 = 15$ 2) $15 \times 3 = 45$ 3) $45 \times 25 = 1125$ 5. Therefore, the final answer is $1125$.