1
JEE Main 2019 (Online) 11th January Evening Slot
+4
-1
Let  S = {1, 2, . . . . . ., 20}. A subset B of S is said to be "nice", if the sum of the elements of B is 203. Then the probability that a randonly chosen subset of S is "nice" is :
A
$${5 \over {{2^{20}}}}$$
B
$${7 \over {{2^{20}}}}$$
C
$${4 \over {{2^{20}}}}$$
D
$${6 \over {{2^{20}}}}$$
2
JEE Main 2019 (Online) 11th January Evening Slot
+4
-1
Out of Syllabus
A bag contains 30 white balls and 10 red balls. 16 balls are drawn one by one randomly from the bag with replacement. If X be the number of white balls drawn, then $$\left( {{{mean\,\,of\,X} \over {s\tan dard\,\,deviation\,\,of\,X}}} \right)$$ is equal to :
A
4
B
$$3\sqrt 2$$
C
$${{4\sqrt 3 } \over 3}$$
D
$$4\sqrt 3$$
3
JEE Main 2019 (Online) 11th January Morning Slot
+4
-1
Two integers are selected at random from the set {1, 2, ...., 11}. Given that the sum of selected numbers is even, the conditional probability that both the numbers are even is :
A
$${2 \over 5}$$
B
$${1 \over 2}$$
C
$${7 \over 10}$$
D
$${3 \over 5}$$
4
JEE Main 2019 (Online) 10th January Evening Slot
+4
-1
Out of Syllabus
If the probability of hitting a target by a shooter, in any shot, is $${1 \over 3}$$, then the minimum number of independent shots at the target required by him so that the probability of hitting the target atleast once is greater than $${5 \over 6}$$ is :
A
4
B
6
C
5
D
3
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