**Could you UNCOVER THE MYSTERY behind the crystal ball?**

**(in the Algebraic way!)**

**Submit your explanation under comments...**

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Multiply 9 with the first digit.

ReplyDeleteThe flash mind reader works with multiples of 9, so all the multiples of 9 is the answer, from 9 to 81, but they are mixed up every time so as to confuse us.

ReplyDeleteThis comment has been removed by the author.

ReplyDeleteDo you mean 9x?

DeleteThis comment has been removed by the author.

DeleteNumber in tens place is x

DeleteNumber in ones place is y

The number =10x+y

10x+y-(x+y)=9x

so the answer is always a multiple of 9

@Zun Kye

DeleteClear explanation :)

5 points for group 4

If n = 82

ReplyDelete82=8x10+2

=8a+2b

10a+2b-(a+2b)

=9a

Therefore, the numbers is a multiple of 9

if you put 8x10+2=8a+2b, it will seem like a=10 and b=1 because 8x10+2=8x10(a)+2x1(b).

DeleteThe answer will still be the same

Delete@Ethan

DeleteThe 3rd line of the working, when generalized (using your example) would be 10a+b

So that it can represent any 2 digit number.

All answers are multiplication of 9 hence taking the number in tens as a and number in ones are b, 10a+b, subtract a+b=9a

ReplyDelete