Question

A padlock has a 4 digit key code

2657 - has two correct digits but neither are in the correct place
0415 - Has one correct digit but it's in the wrong place
4268 - Has no correct digits
1749 - Has two correct digits, both in the correct place.

All the 4 digits in the key are different.
`what is the code for the padlock?

Answer 1

4268 --- Has no correct digits . means key code doesn't consider 4, 2, 6 , 8 .
so, possibilities of digits in key code : 0, 1 , 3 , 5 ,7 and 9 .

again, 1749 --- Has two correct digits and both in the correct place . so, possibilities of correct digits 1 , 7 , 9 [ because 4 can't consider as above explanation ]
Let 1 and 7 are two correct digits and both in the correct place.
but according to condition " 0145--- Has one correct digit and it's in the wrong place " 1 can't be correct digit
so, 7 and 9 are two correct digits and both in the correct place.
now, we have key code __, 7__, 9

now, come to condition " 2657-- has two correct digits but neither are in the correct place " and " 0415 -- has one correct digit but it's in the wrong place.
we get, 5 is one more digit in password which can't place 3rd and 4th place , it means place of it is first .

now, key code is 5, 7, ___, 9
can you say me which is rest to fill 3rd place ?
yep, right !! only 3 is rest to fill 3rd place .

so, the correct key code is 5739

Answer 2

Answer:

5719 seems to be the correct answer!

Step-by-step explanation: