Question

Suppose that a coin is tossed three times. We assume that a coin is fair, so that the heads and
tails are equally likely.
Probability that two heads are obtained in three tosses given that at least one head is
obtained in three tosses is ___________
Probability that that one head is obtained in three tosses given that at most one head
is obtained in three tosses is ____________
at least one means one or more, at most one means one or less.

Answer 1

Ansi- Let x= no. of heads. It is a Binomial distrubution with p. 0'5 % n = 3 → P(x=2[*31) = P(X=2) P( X2) 36.5°5 PCX2) P(x-1)+ P(x-2) + P(x-3) 345.5°+ (;:55+ ?(3:53 10:428 → P(X=1/xsl) = P(X=D P(X=1) 36,.5.5² P(x1) P(X=0) + P(x=1) 36.5953+ 36,.5.5 (P(x-2)- "x po-p)-*) 0.75