tmua.me Medium Set D Paper 2 · Question 6

Two coins are tossed independently. Their probabilities of landing heads are $p$ and $q$ , where $0<p<1$ and $0<q<1$ .

Consider the conditions:

$P$ : $p+q=1$ .
$Q$ : Given that the two coins show the same result, the probability that both show heads is $1/2$ .

Which statement correctly describes $P$ as a condition for $Q$ ?

ANecessary but not sufficient

BBoth necessary and sufficient

CNeither necessary nor sufficient

DSufficient but not necessary

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