Three unbiased coins are tossed. What is the probability of getting at most two heads?
a)3/4
b)1/4
c)3/8
d)7/8

• There are 8 possible out comes out of which only
  Head head head
  is not desired.
  
  so probability = 7/8 ... option d)
• 12 years agoHelpfull: Yes(8) No(3)
• Answer is C.
  
  getting two heads probability would be 3/8
• 12 years agoHelpfull: Yes(3) No(6)
• ans is 7/8
  bcos we r tossing a coin thrice
• 12 years agoHelpfull: Yes(2) No(1)
• Three unbiased coins are tossed.....so probable result S will be -
  S= {(HHT),(HTT),(TTT),(HHH),(THH),(TTH),(HTH),(THT)}
  now E = probability of getting atmost two heads...
  so, P(E)=n(E)/n(S)=3/8. (Ans)
• 10 years agoHelpfull: Yes(1) No(0)
• P(AT MOST 2 HEAD)=N(E)/N(S)
  N(E)=6{HHT,HTT,HTH,THH,TTH,THT}
  N(S)=8
  SO,P(AT MOST 2 HEAD)=6/8=3/4
• 9 years agoHelpfull: Yes(0) No(2)
• Atmost two heads in the sense, it can have two or one or no heads.
  cases:
  no head: 1 (TTT)
  1 head : 3 (HTT, TTH, THT)
  2 heads: 3 (HHT, HTH, THH)
  so in total, there will be 7 choices out of 8.
  
  probability = 7/8
• 7 years agoHelpfull: Yes(0) No(0)