Alter One Digit: Making 2613 Divisible by 4

To solve this problem, we focus on understanding the divisibility rule for 4, which states that a number is divisible by 4 if the number formed by its last two digits is divisible by 4.

Let's explore each option where we change a digit in 2613:

Original number: 2613

• If we replace 6 with 1, the number becomes 2113. Checking divisibility, 13 is not divisible by 4.
• If we replace 2 with 6, the number becomes 6613. Checking divisibility, 13 is not divisible by 4.
• If we replace 1 with 2, the number becomes 2623. Checking divisibility, 23 is not divisible by 4.
• If we replace 6 with 3, the number becomes 2313. Checking divisibility, 13 is not divisible by 4.
• If we replace 6 with 3, the number becomes 2633. Checking divisibility, 33 is not divisible by 4.

Hence the correct way to make the number divisible by 4 is:

Replace 6 with 3 to form the number 2633. The last two digits, 33, are divisible by 4.

The correct choice from the options is Option 4: "Replace 6 with 3."