St Albans Question
Posted: Sun Dec 30, 2012 1:22 pm
I can't copy the image so I'm going to type out the question.
I have the correct answers but I don't understand the logic behind it.
The number "one two one zero" i.e. the number 1210, has a peculiar property,
0 1 2 3 (Digits)
1 2 1 0 (Number)
The first digit is the same as the number of 0's in the number. The second digit i8s the same as the number of 1's in the number, and so on. i.e. the number 1210 has 1 zero, 2 ones, 1 two, and 0 threes.
a) find another 4 digit number with the same property
0 1 2 3 Digits
2 0 2 0 Number (answer is correct)
b) find a five digit number with the same property
0 1 2 3 4 Digits
2 1 2 0 0 Number (answer is correct)
c) find a ten digit number with the same property
0 1 2 3 4 5 6 7 8 9 Digits
6 2 1 0 0 0 1 0 0 0 Number(answer correct)
My son and DH worked out the answers through sheer graft using 'hit and miss theory' and determination, but we need the logic behind it to see how to work out the answer properly.
Any help would be appreciated. Thanks
I have the correct answers but I don't understand the logic behind it.
The number "one two one zero" i.e. the number 1210, has a peculiar property,
0 1 2 3 (Digits)
1 2 1 0 (Number)
The first digit is the same as the number of 0's in the number. The second digit i8s the same as the number of 1's in the number, and so on. i.e. the number 1210 has 1 zero, 2 ones, 1 two, and 0 threes.
a) find another 4 digit number with the same property
0 1 2 3 Digits
2 0 2 0 Number (answer is correct)
b) find a five digit number with the same property
0 1 2 3 4 Digits
2 1 2 0 0 Number (answer is correct)
c) find a ten digit number with the same property
0 1 2 3 4 5 6 7 8 9 Digits
6 2 1 0 0 0 1 0 0 0 Number(answer correct)
My son and DH worked out the answers through sheer graft using 'hit and miss theory' and determination, but we need the logic behind it to see how to work out the answer properly.
Any help would be appreciated. Thanks