1
IIT-JEE 1988
+2
-0.5
One hundred identical coins, each with probability, $$p,$$ of showing up heads are tossed once. If $$0 < p < 1$$ and the probability of heads showing on $$50$$ coins is equal to that of heads showing on $$51$$ coins, then the value of $$p$$ is
A
$$1/2$$
B
$$49/101$$
C
$$50/101$$
D
$$51/101.$$
2
IIT-JEE 1986
+2
-0.5
A student appears for tests, $$I$$, $$II$$ and $$III$$. The student is successful if he passes either in tests $$I$$ and $$II$$ or tests $$I$$ and $$III$$. The probabilities of student passing in tests $$I$$, $$II$$ and $$III$$ are $$p, q$$ and $${1 \over 2}$$ respectively. If the probability that the student is successful is $${1 \over 2}$$, then
A
$$p=q=1$$
B
$$p = q = {1 \over 2}$$
C
$$p=1,$$ $$q=0$$
D
$$p = 1,q = {1 \over 2}$$
3
IIT-JEE 1986
+2
-0.5
The probability that at least one of the events $$A$$ and $$B$$ occurs is $$0.6$$. If $$A$$ and $$B$$ occur simultaneously with probability $$0.2,$$ then $$P\left( {\overline A } \right) + P\left( {\overline B } \right)$$ is
A
$$0.4$$
B
$$0.8$$
C
$$1.2$$
D
$$1.4$$
4
IIT-JEE 1984
+2
-0.5
A box contains $$24$$ identical balls of which $$12$$ are white and $$12$$ are black. The balls are drawn at random from the box one at a time with replacement. The probability that a white ball is drawn for the $$4$$th time on the $$7$$th draw is
A
$$5/64$$
B
$$27/32$$
C
$$5/32$$
D
$$1/2$$
EXAM MAP
Medical
NEET