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Fill in the missing number: 10, 30, 60, 01,__, 12
Use a bit of lateral thinking.
And math.
Also, I do know the answer. Just giving the question as a teaser.

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1 Answer 1

up vote 8 down vote accepted

Let's try reversing the digits:

01, 03, 06, 10, __, 21

Then I see this:

01 + 2 = 03
03 + 3 = 06
06 + 4 = 10
10 + 5 = 15
15 + 6 = 21

As 15 is the answer when the digits are reversed, the missing number in your sequence is 51.

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Yep. That is the answer. Good Job! Now I need to try and get other patterns... –  user360 Jul 27 at 1:32

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