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Coins/Probabilty

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Coins/Probabilty

by venmic » Tue May 10, 2011 8:00 pm
If 5 fair coins are tossed, how many different coin sequences will have exactly 3 tails, if all tails have to occur in a
row?

Please suggest

Thankx
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by manpsingh87 » Tue May 10, 2011 10:16 pm
venmic wrote:If 5 fair coins are tossed, how many different coin sequences will have exactly 3 tails, if all tails have to occur in a
row?

Please suggest

Thankx
{TTT}HH; since all tails have to occur in row so consider them as a one group, therefore in all we have, 3 elements to arrange, {TTT},H,H; which can arrange themselves in 3!/2!=3
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