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a coin is tossed 9 times what is the probability of getting ?
a)five heads
b)at least two heads

 Apr 11, 2020
 #1
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(a): The probability is 9 C 5 / 2^9 = 126 / 512 = 63 / 256....

 

(b): C(9,0)+C(9,1)=1+9=10.

 

512-10=502

 

502/512=251/256.

 Apr 11, 2020
 #2
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The probability to get five heads in 9 flips is (1/2)^5 = 1/32 => 4/32=>1/8

 Apr 12, 2020

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