5 boys & 4 girls sit in a straight line. Find the number of ways in which they can be seated if 2 girls aretogether & the other 2 are also together but separate from the first 2.:
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m balls are distributed among a boys and b girls. Prove that the probability that odd numbers of balls are distributed to boys is `((b+a)^m - (b+a)^m)
Suppose than p and q, respectively, denote the probabilities that a thing goes to a man and a women. `p=(a)/(a+b)and q=(b)/(a+b)` Now, the probabilities of 0,1,2,3,… thing going to men...
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A class consists of 80 students, 25 of them are girls and 55 are boys. If 10 of them are rich and the remaining are poor and also 20 of them are intel
Correct Answer - C Total number of the students is 80. Total number of boys is 55. Therefore are 10 rich, 70 por, 20 intelligent students in the class. Therefore, required...
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A set of parallel chords of the parabola `y^2=4a x` have their midpoint on any straight line through the vertex any straight line through the focus a
Correct Answer - C (3) Let point `P(at_(1)^(2),2at_(1))andQ(at_(2)^(2),2at_(2))` lie on the parabola `y^(2)=4ax`. Here, point P and Q are variable. But the slope of chord PQ, `m_(PQ)=(2)/(t_(1)+t_(2))` Now, let the midpoint...
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Five oys and three girls are sitting in a row of `8` seats. Number of ways in which they can be seated so that not all the girls sit side by side is
Correct Answer - A `(a)` Total no. of arrangement if all the girls do not seat side by side `=["all arrangement"-"girls seat side by side"]` `=8!-(6!xx3!)` `=6!(56-6)=6!xx50` `=720xx50=36000`
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The number of ways in which six boys and six girls can be seated at a round table so that no two girls sit together and two particular girls do not si
Correct Answer - C `(c )` The boys can be seated in `5!` ways. If the girls `g_(1)` and `g_(2)` do not want to sit by the side of `A_(1)` (say)....
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A class has tree teachers, Mr. `X`, Ms.`Y` and Mrs.`Z` and six students `A`, B`, `C`, `D`, `E`, `F`. Number of ways in which they can be seated in a l
Correct Answer - A `(a)` The possible arrangements of teachers and students can be as follows : `(i) T S S T S S T S S` `(ii) S T S...
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Find the number of ways of arranging 15 students `A_1,A_2,........A_15` in a row such that (i) `A_2`, must be seated after `A_1 and A_2`, must come af
Correct Answer - A `(a)` First arrange `12` persons `A_(4),A_(5),….A_(15)` in `"^(15)P_(12)` ways There remains `3` places. Keep `A_(1)` in the first place and arrange `A_(2)`, `A_(3)` in the remaining two...
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A cone is formed by joining together the two straight edges of a sector, so that they coincide with each other. The length of the arc of the sector be
Correct Answer - 0.5 cm
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In a class, the average marks of boys is 520 and that of the girls is 420. If the average marks per student is 500, the percentage of boys in the clas
Correct Answer - ₹80
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In how many ways can 11 members of a committee sit at a round table so that the secretary and the joint secretary are always the neighbours of he pres
Correct Answer - 80640
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