1
IIT-JEE 1998
+2
-0.5
There are four machines and it is known that exactly two of them are faulty. They are tested, one by one, in a random order till both the faulty machines are identified. Then the probability that only two tests are needed is
A
$$1/3$$
B
$$1/6$$
C
$$1/2$$
D
$$1/4$$
2
IIT-JEE 1998
+2
-0.5
If $$E$$ and $$F$$ are events with $$P\left( E \right) \le P\left( F \right)$$ and $$P\left( {E \cap F} \right) > 0,$$ then
A
occurrence of $$E$$ $$\Rightarrow$$ occurrence of $$F$$
B
occurrence of $$F$$ $$\Rightarrow$$ occurrence of $$E$$
C
non-occurrence of $$E$$ $$\Rightarrow$$ non-occurrence of $$F$$
D
none of the above implications holds
3
IIT-JEE 1998
+2
-0.5
Seven white balls and three black balls are randomly placed in a row. The probability that no two black balls are placed adjacently equals
A
$$1/2$$
B
$$7/15$$
C
$$2/15$$
D
$$1/3$$
4
IIT-JEE 1998
+2
-0.5
A fair coin is tossed repeatedly. If the tail appears on first four tosses, then the probability of the head appearing on the fifth toss equals
A
$$1/2$$
B
$$1/32$$
C
$$31/32$$
D
$$1/5$$
EXAM MAP
Medical
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