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?
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?
If numbers are formed using digits 2, 3, 4, 5, 6 without repetition, how many of them will exceed 400?
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!
Evaluate: (8 – 6)!
Compute: `(12!)/(6!)`
Compute: `(12/6)!`
Compute: 3! × 2!
Compute: `(8!)/((6 - 4)!)`
Write in terms of factorial:
6 × 7 × 8 × 9
Find n, if `"n"/(6!) = 4/(8!) + 3/(6!)`
Find n, if (n + 3)! = 110 × (n + 1)!
Find n if: `("n"!)/(3!("n" - 3)!) : ("n"!)/(5!("n" - 5)!)` = 5:3
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)`
Find the value of: `(5(26!) + (27!))/(4(27!) - 8(26!)`
Five balls are to be placed in three boxes, where each box can contain up to five balls. Find the number of ways if no box is to remain empty.
A hall has 12 lamps and every lamp can be switched on independently. Find the number of ways of illuminating the hall.
