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 he select a student if the monitor can be a boy or a girl?
Advertisements
उत्तर
There are 30 boys and 20 girls in a class.
The teacher wants to select a class monitor from these boys and girls.
A boy can be selected in 30 ways and a girl can be selected in 20 ways.
∴ By using the fundamental principle of addition, the number of ways either a boy or a girl is selected as a class monitor = 30 + 20 = 50.
APPEARS IN
संबंधित प्रश्न
How many three-digit numbers can be formed using the digits 2, 3, 4, 5, 6 if digits can be repeated?
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: 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:
3 × 6 × 9 × 12 × 15
Find n, if `1/("n"!) = 1/(4!) - 4/(5!)`
Find n, if (n + 1)! = 42 × (n – 1)!
Find n, if (n + 3)! = 110 × (n + 1)!
Find n if: `("n"!)/(3!("n" - 3)!) : ("n"!)/(5!("n" - 5)!)` = 5:3
Find n if: `("n"!)/(3!("n" - 5)!) : ("n"!)/(5!("n" - 7)!)` = 10:3
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)!`
Find the value of: `(8! + 5(4!))/(4! - 12)`
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.
