Brain Teasers
1-2-6-24
Series
Series teasers are where you try to complete the sequence of a series of letters, numbers or objects.Series
Finish this series:
1-2-6-24-120-??
1-2-6-24-120-??
Hint
6!Answer
7201! = 1
2! = 2
3! = 6
and so on
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Comments
Too easy. I solved it in, like, 5 seconds.
What doees an exclamation mark after a number mean? Please tell me!
The exclamation point indicates "factorial" -
the product of all the integers from 1 up to the number itself.
So 2!=1x2, 3!=1x2x3x4, 4!=1x2x3x4, etc.
the product of all the integers from 1 up to the number itself.
So 2!=1x2, 3!=1x2x3x4, 4!=1x2x3x4, etc.
That should read 3!=1x2x3. Not sure how the typo got in there.
Curiously 0!=1. Can you please explain that one.
0!=1 because of convention. It makes
a number of formulas involving factorials
work out without having to treat 0
as a special case. For example, the
number of ways you can choose k different
objects out of a set of n objects is
n!/((n-k)! * k!). If 0! wasn't 1, then
you would have to treat k=n as a special
case not covered by the formula.
a number of formulas involving factorials
work out without having to treat 0
as a special case. For example, the
number of ways you can choose k different
objects out of a set of n objects is
n!/((n-k)! * k!). If 0! wasn't 1, then
you would have to treat k=n as a special
case not covered by the formula.
this was a good teaser, tho i must admit, as long as you kno that ! is factorial, the hint is basically the answer. i dunno if thats good or bad...LoL
a clearer explaination in the answer would help
but once I got it, it was good
but once I got it, it was good
It started out hard, but the hint helped. Wonderful!
I got it immediately but the math in my head was wrong and I thought it was 840 the riddle I did before was similar to this one so maybe that's why I got it quickly
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