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प्रश्न
Select the correct answer from the given alternatives.
In how many ways 4 boys and 3 girls can be seated in a row so that they are alternate
विकल्प
12
288
144
256
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उत्तर
144
Explanation;
B G B G B G B
4 boys take their seats in 4! ways
3 girls take their seats in 3! ways
Required number = 4! × 3!
= 24 × 6
= 144
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संबंधित प्रश्न
Evaluate: 8!
Evaluate: 10!
Evaluate: (10 – 6)!
Compute: `(12!)/(6!)`
Compute: `(12/6)!`
Compute: (3 × 2)!
Compute: `(9!)/(3! 6!)`
Compute: `(6! - 4!)/(4!)`
Compute: `(8!)/((6 - 4)!)`
Write in terms of factorial.
5 × 6 × 7 × 8 × 9 × 10
Write in terms of factorial.
6 × 7 × 8 × 9
Evaluate : `("n"!)/("r"!("n" - "r")!)` for n = 12, r = 12
Find n, if `"n"/(8!) = 3/(6!) + (1!)/(4!)`
Find n, if `"n"/(6!) = 4/(8!) + 3/(6!)`
Find n, if `(1!)/("n"!) = (1!)/(4!) - 4/(5!)`
Find n, if (n + 3)! = 110 × (n + 1)!
Find n, if: `((17 - "n")!)/((14 - "n")!)` = 5!
Find n, if: `((15 - "n")!)/((13 - "n")!)` = 12
Find n, if: `("n"!)/(3!("n" - 3)!) : ("n"!)/(5!("n" - 5)!)` = 5 : 3
Find n, if: `("n"!)/(3!("n" - 3)!) : ("n"!)/(5!("n" - 7)!)` = 1 : 6
Find n, if: `((2"n")!)/(7!(2"n" - 7)!) : ("n"!)/(4!("n" - 4)!)` = 24 : 1
Show that `("n"!)/("r"!("n" - "r")!) + ("n"!)/(("r" - 1)!("n" - "r" + 1)!) = (("n" + 1)!)/("r"!("n" - "r" + 1)!)`
Show that `(9!)/(3!6!) + (9!)/(4!5!) = (10!)/(4!6!)`
Simplify `((2"n" + 2)!)/((2"n")!)`
Simplify `1/(("n" - 1)!) + (1 - "n")/(("n" + 1)!)`
Simplify `1/("n"!) - 3/(("n" + 1)!) - ("n"^2 - 4)/(("n" + 2)!)`
Select the correct answer from the given alternatives.
Find the number of triangles which can be formed by joining the angular points of a polygon of 8 sides as vertices.
Eight white chairs and four black chairs are randomly placed in a row. The probability that no two black chairs are placed adjacently equals.
If `((11 - "n")!)/((10 - "n")!) = 9,`then n = ______.
3. 9. 15. 21 ...... upto 50 factors is equal to ______.
Let Tn denote the number of triangles which can be formed using the vertices of a regular polygon of n sides. If Tn + 1 – Tn = 21, then n is equal to ______.
