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Utkrisst Shankar
Subject: Maths
, asked on 21/5/18
Q.12. A fair coin is tossed 9 times the probability that at least 5 consecutive heads occurs is
(A)
$\frac{5}{64}$
(B)
$\frac{3}{32}$
(C)
${}^{9}C_{5}{\left(\frac{1}{2}\right)}^{n}$
(D)
$\frac{5}{{2}^{9}}$
Answer
1
Dharunika Vijayakumar
Subject: Maths
, asked on 20/5/18
There are three coins . One is two tailed coin (having tail on both the faces ) another is biased coin that comes up head 60% of the time and third is an unbiased coin . One of the three coins is chosen at random and tossed and it shows tail .So what is the probabilty of that is a two tailed coin ?
Answer
2
Utkrisst Shankar
Subject: Maths
, asked on 20/5/18
A fair coin is tossed 9 times the probability that atleast 5 consicutive heads occurs is
Answer
1
Bhavi Sibal
Subject: Maths
, asked on 13/5/18
Q2
Q.Exercise 2.
(i) In a factory, the workers each of age 20 years or more are grouped as follows
Age beloe (in years)
25
30
35
40
45
50
55
60
No. of workers
32
60
190
236
350
350
380
400
Find the average age of the workers.
Q2
Answer
2
Pranav Shorey
Subject: Maths
, asked on 10/5/18
Please explain:
99. A fair coin is tossed n times. If the probability of getting 7 heads is equal to the probability of getting 9 heads, then the value of n will be.
(a) 8 (b) 13
(c) 15 (d) None of these.
Answer
2
Prithesh Dwivedi
Subject: Maths
, asked on 5/5/18
The probability that a man can hit a target is ¾ and the probability that he will hit at least n-1 time is 189/256, then the number of times , n he tried is
Answer
1
B Ashwini
Subject: Maths
, asked on 25/4/18
List important formulas from class 11th & 12th Maths for competitive exams!!!
Answer
1
Bhavi Sibal
Subject: Maths
, asked on 23/4/18
Q3
Q3. A couple has 2 children. Find the probability that both are boys, if it known that (i) one of the children is a boy; (ii) the older is a boy.
Answer
1
Bhavi Sibal
Subject: Maths
, asked on 23/4/18
There are four events A,B,C and D , one of which must and only one can happen.The odds are 2:5 in favour of A, 3:4 in favour of B and 3:1 against C . Find odds against D.
Answer
1
Bhavya Jain
Subject: Maths
, asked on 23/4/18
Can you please solve this question along with telling general approach for such pattern of questions?
Q.5. If
$\left(1+x+{x}^{2}+{x}^{3}\right){x}^{5}={}_{k=0}{}^{15}a_{k}{x}^{k}then{}_{k=0}{}^{7}a_{2k}$
is equal to
(a) 128
(b) 256
(c) 512
(d) 1024
Answer
2
Muhammad Arafath R Z
Subject: Maths
, asked on 18/4/18
Permutations online mains 2018
Q.1. The number of four letter words that can be formed using the letters of the word
BARRACK
is :
a. 270
b. 264
c. 120
d. 144
Answer
1
Laieeqa
Subject: Maths
, asked on 15/4/18
Solve this:
26. If coefficient of variation is 60 and standard deviation is 24, then Arithmetic mean is
(A) 7/20 (B) 40
(C) 20/7 (D) 1/40
Answer
1
Manasi Mujumdar
Subject: Maths
, asked on 3/4/18
Q. For two data sets, each of size 6, the variances are 4 and 6 and the means are 3 and 5. The variance of the combined data set is
6
7
7.5
5
Answer
1
Mitali
Subject: Maths
, asked on 27/3/18
Do we represent the probability that at least one of the events A and B occurs as P(A)+P(B)-2P(A int. B)
Answer
1
Chaitanya Kapoor
Subject: Maths
, asked on 26/3/18
Solve this:
11. What is the probability of getting five heads and seven tails in 12 flips of a balance coin?
(a) C(12,5)/(2
^{5}
) (b) C(12,5)/(2
^{7}
)
(d) C(12,5)/(2
^{12}
) (d) (a) C(12,7)/(2
^{6}
)
Answer
1
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Next
What are you looking for?

(A) $\frac{5}{64}$

(B) $\frac{3}{32}$

(C) ${}^{9}C_{5}{\left(\frac{1}{2}\right)}^{n}$

(D) $\frac{5}{{2}^{9}}$

Q.Exercise 2.(i) In a factory, the workers each of age 20 years or more are grouped as follows

Find the average age of the workers.

Q2

99. A fair coin is tossed n times. If the probability of getting 7 heads is equal to the probability of getting 9 heads, then the value of n will be.

(a) 8 (b) 13

(c) 15 (d) None of these.

Q3. A couple has 2 children. Find the probability that both are boys, if it known that (i) one of the children is a boy; (ii) the older is a boy.

Q.5. If $\left(1+x+{x}^{2}+{x}^{3}\right){x}^{5}={}_{k=0}{}^{15}a_{k}{x}^{k}then{}_{k=0}{}^{7}a_{2k}$ is equal to

(a) 128

(b) 256

(c) 512

(d) 1024

Q.1. The number of four letter words that can be formed using the letters of the word

BARRACKis :a. 270

b. 264

c. 120

d. 144

26. If coefficient of variation is 60 and standard deviation is 24, then Arithmetic mean is

(A) 7/20 (B) 40

(C) 20/7 (D) 1/40

11. What is the probability of getting five heads and seven tails in 12 flips of a balance coin?

(a) C(12,5)/(2

^{5}) (b) C(12,5)/(2^{7})(d) C(12,5)/(2

^{12}) (d) (a) C(12,7)/(2^{6})