Sign in to follow this  
Followers 0

Combination Lock

SOLVED   1 vote

  1. 1. Solved by

    • Molly Mae
      1
    • in post #2
      0

Please sign in or register to vote in this poll.

10 posts in this topic

Posted · Report post

Here's an easy-ish one...

This combination lock uses digits 0-9

-[?]-[?]-[?]-[?]-

1. The first digit is a prime number.

2. The second digit is not a factor of 12.

3. The third digit is greater than the second digit.

4. The fourth digit is one greater than another digit.

5. There is exactly one odd digit.

6. No two digits are the same.

What is twice the sum of the digits?

-1

Share this post


Link to post
Share on other sites

Posted · Report post

1. The first digit is a prime number.-- 2, 3, 5, 7

2. The second digit is not a factor of 12.-- 5, 7, 8

3. The third digit is greater than the second digit.-- 6, 7, 8, 9

4. The fourth digit is one greater than another digit. -- 3, 4, 6, 7, 8, 9

5. There is exactly one odd digit.

6. No two digits are the same.

The second or third digit must be the odd one, so the first number must be 2. The second number must be 5--can't be 7+ because two numbers must be higher than it and not odd. The third digit must be > 5 but even (leaving 6 and 8). Not 6 because that would make the last digit odd. Third must be 8 and fourth must be 6.

2 - 5 - 8 - 6

42 is twice the sum of the digits.

2

Share this post


Link to post
Share on other sites

Posted · Report post

2-5-6-8 42 is the answer

0

Share this post


Link to post
Share on other sites

Posted · Report post

2-5-6-8 42 is the answer

oops read 4 wrong but it still works

0

Share this post


Link to post
Share on other sites

Posted (edited) · Report post

42

by (1), (2), (5) and (6), the first two digits are in this set: 25, 27, 28, 29, 38, 58, 78

(3) rules out 29

(3) and (4) together rule out 78 25, 27, 28, 38, 58

All combinations obeying (3) and (5): 256, 258, 278, 289

all combinations matching (4): 2563, 2567, 2583, 2586, 2589, 2783, 2789, 2893

removing (5) violators 2586

sum of digits = 21, twice that is 42

Edit: looks like I got here late. Gotta remember to refresh the screen before posting (note to self...)

Edited by CaptainEd
0

Share this post


Link to post
Share on other sites

Posted (edited) · Report post

wel.. mutiple possibilities. or multiple Qs

2083.. 0 is an even no and 0 is not a factor of 12 and for that matter any number..... so twice the sum of digits will be 26

Edited by hhh3
0

Share this post


Link to post
Share on other sites

Posted · Report post

The combination -7-0-6-8- giving 42 as twice the sum also works. So does -2-0-3-4- giving 18 as twice the sum. There are others which have 0 as the second digit.

0

Share this post


Link to post
Share on other sites

Posted · Report post

42. The combo I found was 2 5 8 6, their sum is 21, twice that is 42.

0

Share this post


Link to post
Share on other sites

Posted · Report post

MM got it in post #2.

In working out the puzzle, 0 vanished from #2's possibilities in an earlier form of the rules and I must have forgotten to return it. Sorry for the confusion.

0

Share this post


Link to post
Share on other sites

Posted · Report post

the number is 2586 which adds nd doubles to 42

0

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0

  • Recently Browsing   0 members

    No registered users viewing this page.