Question

Calculate the check digit for the following card number: 4264 5120 0336 214d.

A) 2
B) 5
C) 3
D) 4

Answer 1

To calculate the check digit for the given card number, we can use the Luhn algorithm. The check digit for the card number 4264 5120 0336 214d is 1.

Step-by-step explanation:

To calculate the check digit for the card number 4264 5120 0336 214d, we can use the Luhn algorithm. The Luhn algorithm is a widely used formula for validating identification numbers, such as credit card numbers. Here are the steps to calculate the check digit:

1. Starting from the rightmost digit, double every second digit. For example, double the 4 in the second-to-last position, giving us 8.
2. If any of the doubled digits are greater than 9, subtract 9 from them. In this case, 8-9 = -1, so the digit becomes 1.
3. Add up all the digits, including the doubled digits. In this case, the sum is 4+2+6+1+5+1+2+0+0+3+3+6+2+1+4+1+2=49.
4. The check digit is the number needed to make the sum a multiple of 10. In this case, 49 + X = 50, where X is the check digit. Solving for X, we find X = 1.

Therefore, the correct check digit for the card number 4264 5120 0336 214d is 1.