Advertisements
Advertisements
प्रश्न
Evaluate `("n"!)/("r"!("n" - "r")!)` when n = 6, r = 2
Advertisements
उत्तर
n = 6 , r = 2
`("n"!)/("r"!("n" - "r")!) = (6!)/(2!(6 - 2)!)`
= `(6!)/(2!4!)`
= `(6 xx 5xx 4!)/(2 xx 1 xx 4!)`
= `(6 xx 5)/2`
= 3 × 5
= 15
APPEARS IN
संबंधित प्रश्न
Given 5 flags of different colours, how many different signals can be generated if each signal requires the use of 2 flags, one below the other?
How many two letter words can be formed using letters from the word SPACE, when repetition of letters is allowed?
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 girl or a boy?
How many two letter words can be formed using letters from the word SPACE, when repetition of letters is allowed?
How many three-digit numbers can be formed from the digits 0, 1, 3, 5, 6 if repetitions of digits are not allowed?
In a test, 5 questions are of the form 'state, true or false'. No student has got all answers correct. Also, the answer of every student is different. Find the number of students appeared for the test.
How many numbers between 100 and 1000 have 4 in the units place?
How many four digit numbers will not exceed 7432 if they are formed using the digits 2, 3, 4, 7 without repetition?
How many words can be formed by writing letters in the word CROWN in different order?
A mobile phone has a passcode of 6 distinct digits. What is the maximum number of attempts one makes to retrieve the passcode?
Count the numbers between 999 and 10000 subject to the condition that there are at least one of the digits is repeated
Find the value of `(12!)/(9! xx 3!)`
Find the value of n if (n + 1)! = 20(n − 1)!
Choose the correct alternative:
The sum of the digits at the 10th place of all numbers formed with the help of 2, 4, 5, 7 taken all at a time is
Choose the correct alternative:
The number of five digit telephone numbers having at least one of their digits repeated i
Choose the correct alternative:
The number of 10 digit number that can be written by using the digits 2 and 3 is
In an examination there are three multiple choice questions and each question has 4 choices. Number of ways in which a student can fail to get all answer correct is ______.
Find the number of integers greater than 7000 that can be formed with the digits 3, 5, 7, 8 and 9 where no digits are repeated.
The number of six-digit numbers, all digits of which are odd is ______.
