Arnold K H Tan's answer to Prateek's Secondary 1 Maths Singapore question.
Using the middle number as an even integer x is more straightforward.
Sum of numbers
= (x - 2) + x + (x + 2)
= x - 2 + x + x + 2
= 3x
which contains a multiplier 3 and therefore the sum is divisible by 3.
Sum of numbers
= (x - 2) + x + (x + 2)
= x - 2 + x + x + 2
= 3x
which contains a multiplier 3 and therefore the sum is divisible by 3.
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