Counting

 

A fair coin is tossed 12 times.  How many different sequences of tosses could there have been, if the number of tosses was at least     

 

The number is 2¹²  =  4096     

 

If you toss it 1 time,   the possible sequences is  2¹ = 2 ... either H or T     

If you toss it 2 times, the possible sequences is  2² = 4 ... HH, TT, HT, TH     

If you toss it 3 times, the possible sequences is  2³ = 8 ... HHH, HHT, HTH, THH, TTT, TTH, THT, HTT     

 

and so on     

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