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Sat 15 Oct, 2011 06:27 am
Which digits or numbers belong logically on the letters X, Y en Z in the sequence below and why?
1+1=2, 1+3=4, 1+7=8, 1+9=10, 2+3=5, 2+9=11, X+Y=Z, …
@whimsical,
Hi Whim!
3+1=4, 3+7=10, 4+1=5, 4+3=7, 4+7=11
Concatenate the two numbers being added. They should look familiar (11, 13, 17, 19, 23, 29) because they are consecutive primes.