Find the difference between the largest 7-digit number and the smallest 7-digit number formed by using the digits 4, 0, 3, 9 and 7 (using each digit at least once).

1. 6993951
2. 6949530
3. 6963951
4. 6996951

The Correct option is D

Explanation:

To find the difference between the largest and smallest 7-digit numbers using the digits 4, 0, 3, 9, and 7 (each used at least once), follow the steps given below:

Step 1: Digits we have

The digits are 4, 0, 3, 9, and 7.

Step 2: Make the largest 7-digit number

To make the biggest number, put the digits in order from biggest to smallest. We need 7 digits, but we only have 5, so we repeat some digits.

Use 9 three times, 7 two times, and 4 and 3 once each.

The largest number is 9997443.

Step 3: Make the smallest 7-digit number

To make the smallest number, put digits in order from smallest to biggest, but the first digit cannot be 0 because then it would not be a 7-digit number.

Start with 3 (smallest number after 0), then use 0 three times, then 4 and 7.

The smallest number is 3000047.

Step 4: Find the difference

Subtract the smallest number from the largest number:

9997443 − 3000047 = 6997396

Final answer:

The difference between the largest and smallest 7-digit numbers is 6,997,396.