Question

Detective Brown is trying to decode a password. It contains the digits 1, 2, 3, 4, and 5 arranged in a certain sequence.
The last digit is 3, and the first digit is 1.
If all the digits are used once and the sum of the first two digits is the 3rd digit itself, what is the password?

• A. 1 4 5 3 2
• B. 1 4 5 2 3
• C. 1 5 2 4 3
• D. 1 5 4 2 3

Answer 1

The correct option is B 1 4 5 2 3

From the question, we know that the first digit of the password is 1 and the last digit is 3.


The sum of the first two digits of the password should be equal to its 3rd digit.

1 + ? = ?

The only digits remaining are 2, 4, and 5.

Thus, let's substitute each of these values to find the second and third digits.

1 + 2 = 3

But 2 cannot be the second digit because 3 is already the last digit of the password.

1 + 4 = 5

and

1 + 5 = 6

But 5 cannot be the third digit as 6 is not one of the digits of the password.

So, the second digit has to be 4, and the third digit has to be 5.


The only remaining digit is 2. Thus, it must be the fourth digit.

Hence, the correct password is: