Advertisements
Advertisements
प्रश्न
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?
Advertisements
उत्तर
Since the teacher wants to select a class monitor that must be a boy and there are 30 boys in a class.
∴ Total number of ways of selecting boy monitor
= 30 ways.
Since the teacher wants to select a class monitor that must be a girl and there are 20 girls in a class.
∴ Total number of ways of selecting girl monitor
= 20 ways.
APPEARS IN
संबंधित प्रश्न
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!
Evaluate: 8! – 6!
Evaluate: (8 – 6)!
Compute: `(12!)/(6!)`
Compute: `(12/6)!`
Compute: 3! × 2!
Compute: `(9!)/(3! 6!)`
Write in terms of factorial:
3 × 6 × 9 × 12 × 15
Evaluate: `("n"!)/("r"!("n" - "r"!)` For n = 12, r = 12
Find n, if (n + 1)! = 42 × (n – 1)!
Find n if: `("n"!)/(3!("n" - 3)!) : ("n"!)/(5!("n" - 5)!)` = 5:3
Find n, if: `((17 - "n")!)/((14 - "n")!)` = 5!
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: `(9!)/(3!6!) + (9!)/(4!5!) = (10!)/(4!6!)`
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.
