Brain Teasers
3, 4, 5, 5, 5, 6, 7, 7, 7, ?
What's the next number in this series?
3, 4, 5, 5, 5, 6, 7, 7, 7, ?
3, 4, 5, 5, 5, 6, 7, 7, 7, ?
Answer
8.The nth entry is the nth composite number minus n.
3=4-1, 4=6-2, 5=8-3, 5=9-4, 5=10-5, 6=12-6, 7=14-7, 7=15-8, 7=16-9, 8=18-10.
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Comments
I got is correct but in a very simple way: +1+1+0+0+1+1+0....and so on.
The answer confused me....
The answer confused me....
Both series work the same for a while... using the +1+1+0+0 series you'd get
3,4,5,5,5,6,7,7,7,8,9,9,9,10,11,11,11...
using nth composite - n you'd get
3,4,5,5,5,6,7,7,7,8,9,9,9,10,10,10,10...
it's when n=15 that things fall apart
3,4,5,5,5,6,7,7,7,8,9,9,9,10,11,11,11...
using nth composite - n you'd get
3,4,5,5,5,6,7,7,7,8,9,9,9,10,10,10,10...
it's when n=15 that things fall apart
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