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Find the smallest positive multiple of nine containing only even digits.

 Dec 15, 2019

Best Answer 

 #1
avatar+245 
+2

i don't have a logical way of solving this, i just did 9+9+9... until i found a number with even digits :) i think the answer is 288.

 

ps. i didn't do that in my head i don't have enough brain cells to add 9 until 288 lol

 Dec 15, 2019
 #1
avatar+245 
+2
Best Answer

i don't have a logical way of solving this, i just did 9+9+9... until i found a number with even digits :) i think the answer is 288.

 

ps. i didn't do that in my head i don't have enough brain cells to add 9 until 288 lol

atlas9 Dec 15, 2019
 #2
avatar+108790 
+2

I did it in  a similar way only I looked for little shortcuts

 

In order for a number to be divisable by 9 its digits must add to a multiple of 9

For 2 digit numbers it is impossible for them both to be even

 

So I wll consider 3 digit numbers

207 is the smallest one with the first digit even. 

If the first digit is 2 then the last two digits add to 7 or 16.

  Adding to 7 is no good, no 2 even numbers add to 7

   What even numbers add to 16  ?     8 and 8 are the only ones.

 

So the answer must be 288

 Dec 15, 2019

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