Elitmus
Exam
Numerical Ability
Probability
8 coins are tossed. Whats is the probability that one and only one turns up head ?
Options
1) 1/256
2) 1/32
3) 1/64
4) 1/128
Read Solution (Total 9)
-
- 8/2^8=8/256=1/32. where 2^8 is the sample space and we cn get only one head in 8 ways..So answer is (2).
- 9 years agoHelpfull: Yes(23) No(1)
- total number of outcomes = 2^8 = 256
number of favourable outcomes = 8. { TTTTTTTH, TTTTTTHT, TTTTTHTT, TTTTHTTT, TTTHTTTT, TTHTTTTT, THTTTTTT, HTTTTTTT }
answer = 8/256 = 1/32 - 9 years agoHelpfull: Yes(19) No(1)
- 8c1(1/2)(1/2)^7=1/32
- 9 years agoHelpfull: Yes(6) No(1)
- One head and seven tails would have eight positions where the head can come.
Thus, 8 × (1/2)8 = (1/32) - 8 years agoHelpfull: Yes(1) No(0)
- only one turns up head in 8 times the n0 of event is 8
HTTTTTTT THTTTTTT TTHTTTTT TTTHTTTT TTTTHTTT TTTTTHTT TTTTTTHT TTTTTTTH
AND TOTAL OUTCOMES IS 2^8 = 256
required probability = 8/256, = 1/32
hence option 2 is correct
- 8 years agoHelpfull: Yes(1) No(0)
- 8 coin tossed=n(s)=2^8=256
Prob of getting only 1 head is n(e)=8
Therefore n(e)/n(s)=8/256=1/32 - 8 years agoHelpfull: Yes(1) No(0)
- 1/32 because in 8 ways only one head can come and there are 256 total outcomes therefore probability is 1/32.
- 5 years agoHelpfull: Yes(1) No(0)
- 8c1*((1/2)^1)*((1/2)^7)=1/32
- 8 years agoHelpfull: Yes(0) No(0)
- 8c1/2(pw8) ans
- 8 years agoHelpfull: Yes(0) No(0)
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