Q. 84.0( 20 Votes )

# Three coins are tossed once. Find the probability of getting

(i) 3 heads

(ii) 2 heads

(iii) at least 2 heads

(iv) at most 2 heads

(v) no head

(vi) 3 tails

(vi) exactly two tails

(vii) (viii) no tail

(viii) (ix) at most two tails

Answer :

When three coins are tossed then S = {HHH, HHT, HTH, THH, TTH, HTT, TTT, THT}

Where s is sample space and here n(S) = 8

Let A be the event of getting 3 heads

n(A)= 1

Let A be the event of getting 2 heads

n (A) = 3

Let A be the event of getting at least 2 head

n(A) = 4

•let A be the event of getting at most 2 heads

n(A) = 7

•Let A be the event of getting no heads

n(A) = 1

(vi) Let A be the event of getting 3 tails

n(A) = 1

(vii) Let A be the event of getting exactly 2 tails

n(A) = 3

(viii) Let A be the event of getting no tails

n(A) = 1

(ix) Let A be the event of getting at most 2 tails

n(A) = 7

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