1
IIT-JEE 2006
+5
-1.25
There are $$n$$ urns, each of these contain $$n+1$$ balls. The ith urn contains $$i$$ white balls and $$(n+1-i)$$ red balls. Let $${u_i}$$ be the event of selecting ith urn, $$i=1,2,3........,n$$ and $$w$$ the event of getting a white ball.

If $$P\left( {{u_i}} \right) = c,$$ (a constant) then $$P\left( {{u_n}/w} \right) =$$

A
$${2 \over {n + 1}}$$
B
$${1 \over {n + 1}}$$
C
$${n \over {n + 1}}$$
D
$${1 \over 2}$$
2
IIT-JEE 2005 Screening
+2
-0.5
A six faced fair dice is thrown until $$1$$ comes, then the probability that $$1$$ comes in even no. of trials is
A
$$5/11$$
B
$$5/6$$
C
$$6/11$$
D
$$1/6$$
3
IIT-JEE 2004 Screening
+2
-0.5
If three distinct numbers are chosen randomly from the first $$100$$ natural numbers, then the probability that all three of them are divisible by both $$2$$ and $$3$$ is
A
$$4/25$$
B
$$4/35$$
C
$$4/33$$
D
$$4/1155$$
4
IIT-JEE 2003 Screening
+2
-0.5
Two numbers are selected randomly from the set $$S = \left\{ {1,2,3,4,5,6} \right\}$$ without replacement one by one. The probability that minimum of the two numbers is less than $$4$$ is
A
$$1/15$$
B
$$14/15$$
C
$$1/5$$
D
$$4/5$$
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