Final answer:
The expression 65×40÷(___+5)×5 can be correctly filled using Option B, which is the number 5. After calculating, it yields the whole number 260, which aligns with the provided options and shows that Option B is the correct fill for the blank.
Step-by-step explanation:
To solve this, let's replace the blank with the options given and check which one will yield a correct mathematical result.
For simplicity, let's calculate the expression without the blank first: 65×40×5 = 65×200 = 13000.
Now, we only need to find (___+5) that, when you divide 13000 by this number times 5, yields a whole number result.
- Option A (4): 13000÷((4+5)×5) = 13000÷(9×5) = 13000÷45 = 288.888..., not a whole number.
- Option B (5): 13000÷((5+5)×5) = 13000÷(10×5) = 13000÷45 = 260, which is a whole number and fits well.
- Options C and D will yield larger denominators, and thus, smaller results, also not whole numbers.
Hence, the correct answer is Option B (5).