SOLUTION: If21y 8 is multiple of 6,where y is a digit, them what is the value (S)of y?

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Question 792493: If21y 8 is multiple of 6,where y is a digit, them what is the value (S)of y?
Answer by KMST(5328) About Me  (Show Source):
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A number whose digits (in order) are 2, 1, y, and 8 is obviously even (multiple of 2).
For that number to be a multiple of 6, it has to also be a multiple of 3.
To be a multiple of 3, the sum of the digits must be a multiple of 3,
so 2%2B1%2By%2B8=11%2By must be a multiple of 3
The choices are
11%2By=12 --> y=1, or
11%2By=15 --> y=4, or
11%2By=18 --> y=7
The value of that digit will be 10y
In 2118, y=1 and the value of y in that number is 10.
In 2148, y=4 and the value of y in that number is 40.
In 2178, y=7 and the value of y in that number is 70.