1
WB JEE 2019
MCQ (Single Correct Answer)
+1
-0.25
Change Language
If X is a random variable such that $$\sigma$$(X) = 2.6, then $$\sigma$$(1 $$-$$ 4X) is equal to
A
7.8
B
$$-$$ 10.4
C
13
D
10.4
2
WB JEE 2018
MCQ (Single Correct Answer)
+1
-0.25
Change Language
In order to get a head at least once with probability $$ \ge $$ 0.9, the minimum number of times a unbiased coin needs to be tossed is
A
3
B
4
C
5
D
6
3
WB JEE 2018
MCQ (Single Correct Answer)
+1
-0.25
Change Language
A student appears for tests I, II and III. The student is successful if he passes in tests I, II or I, III. The probabilities of the student passing in tests I, II and III are respectively p, q and 1/2. If the probability of the student to be successful is 1/2. Then
A
p (1 + q) = 1
B
q (1 + p) = 1
C
pq = 1
D
$${1 \over p} + {1 \over q} = 1$$
4
WB JEE 2017
MCQ (Single Correct Answer)
+1
-0.25
Change Language
The probability that a non-leap year selected at random will have 53 Sunday is
A
0
B
1/7
C
2/7
D
3/7
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Medical
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Graduate Aptitude Test in Engineering
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CBSE
Class 12