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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
पर्याय
12
288
144
256
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
APPEARS IN
संबंधित प्रश्न
Evaluate: 8!
Evaluate: 10!
Evaluate: 10! – 6!
Compute: `(12!)/(6!)`
Compute: (3 × 2)!
Compute: `(9!)/(3! 6!)`
Compute: `(6! - 4!)/(4!)`
Compute: `(8!)/(6! - 4!)`
Compute: `(8!)/((6 - 4)!)`
Write in terms of factorial.
5 × 6 × 7 × 8 × 9 × 10
Write in terms of factorial.
3 × 6 × 9 × 12 × 15
Evaluate : `("n"!)/("r"!("n" - "r")!)` for n = 8, r = 6
Evaluate : `("n"!)/("r"!("n" - "r")!)` for n = 12, r = 12
Find n, if `"n"/(8!) = 3/(6!) + (1!)/(4!)`
Find n, if `(1!)/("n"!) = (1!)/(4!) - 4/(5!)`
Find n, if (n + 1)! = 42 × (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 `((2"n")!)/("n"!)` = 2n (2n – 1)(2n – 3) ... 5.3.1
Simplify `((2"n" + 2)!)/((2"n")!)`
Simplify `("n" + 2)/("n"!) - (3"n" + 1)/(("n" + 1)!)`
Simplify `1/("n"!) - 3/(("n" + 1)!) - ("n"^2 - 4)/(("n" + 2)!)`
Simplify `("n"^2 - 9)/(("n" + 3)!) + 6/(("n" + 2)!) - 1/(("n" + 1)!)`
In how many ways can 10 examination papers be arranged so that the best and the worst papers never come together?
Answer the following:
Find the number of words that can be formed by using all the letters in the word REMAIN If these words are written in dictionary order, what will be the 40th word?
Find the number of integers greater than 7,000 that can be formed using the digits 4, 6, 7, 8, and 9, without repetition: ______
If `((11 - "n")!)/((10 - "n")!) = 9,`then n = ______.
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 ______.
