Question

1. A bank password consists of two letters of the English al-
phabet followed by two digits. How many different pass-
words are there?​

Answer 1

Answer:

Given,

Bank Password has 2 English alphabet letters and 2 Digits

PASSWORD = [ _ ] [ _ ] [ _ ] [ _ ]

Digit - 1 & 2 are Alphabets while Digit - 3 & 4 are digits

We know,

No of alphabets = 26 ( A through z)

No. of digits = 10 ( 0 through 9)

Here,

There are 2 cases to be considered:

• CASE - 1:

WITHOUT REPETITION:

Of the 4 digits of Password,

- Digit 1 can be filled in 26 ways

- Digit 2 can be filled in 26 ways

- Digit 3 can be filled in 10 ways

-Digit 4 can be filled in 10 ways.

•°• Total No. of ways possible = 26×26×10×10 = 676× 100 = 67600

• CASE -2 :

WITH REPETITION:

Of the 4 digits of the password

- Digit 1 can be filled in 26 ways

- Digit 2 can be filled in 25 ways

(Excluding Digit 1)

- Digit 3 can be filled in 10 ways

-Digit 4 can be filled in 9 ways.

(Excluding Digit 2)

•°• Total No. of ways possible = 26×25×10×9 = 58500

Answer 2

Answer:

6804532.

Step-by-step explanation:

6804532. this is the ans please mark me brilliant