what is the probability of getting two consecutive heads in 5 tosses of an unbiased coin?
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6 Answers
lets calculate for non consecutive
For all 5 tails , no. of ways=1
for 4 tails no. of ways=5
for 3 tails no. of ways=6 (find it how)
for 2 tails no. of ways is 1 (which one)
for 1 tail no way
for 0 tail no way
so total no. of ways=1+5+6+1=13
probability, p=13/32
probability of getting two consecutive heads=1-p=19/32
Cases: We have 2 heads
no of ways = 4
When we have 3 heads, The number of ways of getting 2 consecutive heads is 3+ 2 + 2 ways
When we have 4 heads then the number of ways of getting 2 consecutive heads is 5
If there is 5 head, the number of ways of getting 2 consective heads is 1
So the toal way sof getting heads is 13
total ways of getting the 5 coins tossed is 32
Probability is 13/32
but if it is atleast...then it should be...
HH*** 8 cases
THH** 4 cases
*THH* 4 cases
**THH 4 cases
Total no. of favourable cases 20
probability=20/32=5/8