MEDIUM
11th CBSE
IMPORTANT
Earn 100

Out of 18 points in a plane, no three are in the same straight line except five points which are collinear. How many (i) straight lines (ii) triangles can be formed by joining them?

Important Questions on Combinations

EASY
11th CBSE
IMPORTANT
MATHEMATICS for CLASS XI>Chapter 17 - Combinations>EXERCISE 17.3>Q 1
How many different words, each containing 2 vowels and 3 consonants can be formed with 5 vowels and 17 consonants?
EASY
11th CBSE
IMPORTANT
MATHEMATICS for CLASS XI>Chapter 17 - Combinations>EXERCISE 17.3>Q 2
There are 10 persons named P1, P2, P3, ….., P10. Out of 10 persons, 5 persons are to be arranged in a line such that each arrangement P1 must occur whereas P4 and P5 do not occur. If the number of such possible arrangements is 7C4×m! then find the value of m.
EASY
11th CBSE
IMPORTANT
MATHEMATICS for CLASS XI>Chapter 17 - Combinations>EXERCISE 17.3>Q 3

How many words, with or without meaning can be formed from the letters of the word MONDAY, assuming that no letter is repeated, if 4 letters are used at a time

EASY
11th CBSE
IMPORTANT
MATHEMATICS for CLASS XI>Chapter 17 - Combinations>EXERCISE 17.3>Q 3
How many words, with or without meaning can be formed from the letters of the word MONDAY, assuming that no letter is repeated, if all letters are used at a time. (Write only numerical value)
EASY
11th CBSE
IMPORTANT
MATHEMATICS for CLASS XI>Chapter 17 - Combinations>EXERCISE 17.3>Q 3

How many words, with or without meaning can be formed from the letters of the word MONDAY, assuming that no letter is repeated, if all letters are used but first letter is vowel.

MEDIUM
11th CBSE
IMPORTANT
MATHEMATICS for CLASS XI>Chapter 17 - Combinations>EXERCISE 17.3>Q 4
Find the value of k if the number of permutations of n distinct things taken r together, in which 3 particular things must occur together is  n-kCr-k(r-2)!·k!.
EASY
11th CBSE
IMPORTANT
MATHEMATICS for CLASS XI>Chapter 17 - Combinations>EXERCISE 17.3>Q 5
How many words each of 3 vowels and 2 consonants canbe formed from the letters of the word INVOLUTE?
MEDIUM
11th CBSE
IMPORTANT
MATHEMATICS for CLASS XI>Chapter 17 - Combinations>EXERCISE 17.3>Q 6
Find the value of k if the number of permutations of n different things taken r at a time such that two specified things occur together is  n-kCr-k(r-1)!·k!