Question

Correct answers only please!

Answer 1

Answer:

  B.  3×10^13

Step-by-step explanation:

The first two digits are fixed at one of three pairs of values; the last digit is "fixed" as the check digit, leaving 16 - 3 = 13 free digits. These can take on any of 10^13 values.

The total number of possible card numbers is 3×10^13.

Answer 2

Answer:

The correct option is B.

Step-by-step explanation:

Total possible digits are 0,1,2,3,4,5,6,7,8,9.

Total number of digits in a credit card = 16

It is given that that the last digit of credit card is fixed.

Total number of possible ways for 16th digit = 1

U-Kan-Trust-Us Credit Card numbers begin with 61, 62, or 63.

Total number of possible ways for first two digits = 3

Remaining places = 16 - 1 - 2 = 13

In these 13 remaining places any of 10 digits can be occur.

Total number of possible ways for remaining 13 digits = $10^{13}$

The maximum number of credit cards that UKTU can issue is

$Total =3\times (10^{13})\times 1$

$Total =3(10^{13})$

Therefore the correct option is B.