Advertisements
Advertisements
Question
Compute: `(9!)/(3! 6!)`
Advertisements
Solution
`(9!)/(3! 6!)` = `(9 xx 8 xx 7 xx 6!)/((3xx2xx1)xx6!)`
= `(9 xx 8 xx 7)/(3 xx 2 xx 1)`
= 84
APPEARS IN
RELATED QUESTIONS
A teacher wants to select the class monitor in a class of 30 boys and 20 girls, in how many ways can the monitor be selected if the monitor must be a boy? What is the answer if the monitor must be a girl?
How many five-digit numbers formed using the digit 0, 1, 2, 3, 4, 5 are divisible by 3 if digits are not repeated?
Evaluate: 8! – 6!
Evaluate: (8 – 6)!
Compute: (3 × 2)!
Compute: `(8!)/(6! - 4!)`
Write in terms of factorial:
5 × 6 × 7 × 8 × 9 × 10
Write in terms of factorial:
6 × 7 × 8 × 9
Write in terms of factorial:
5 × 10 × 15 × 20 × 25
Find n, if `"n"/(6!) = 4/(8!) + 3/(6!)`
Find n, if `1/("n"!) = 1/(4!) - 4/(5!)`
Find n if: `("n"!)/(3!("n" - 5)!) : ("n"!)/(5!("n" - 7)!)` = 10:3
Find n, if: `((15 - "n")!)/((13 - "n")!)` = 12
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: `((2"n")!)/("n"!)` = 2n(2n – 1)(2n – 3)....5.3.1
A student passes an examination if he/she secures a minimum in each of the 7 subjects. Find the number of ways a student can fail.
A hall has 12 lamps and every lamp can be switched on independently. Find the number of ways of illuminating the hall.
