Class 11

Math

JEE Main Questions

Permutations and Combinations

Find the number of permutations of the letters of the word ALLAHABAD.

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Let $f(n)=r=0∑n k=r∑n (kr)˙$ Find the total number of divisors of $f(9)˙$

How many 4-digit numbers can be formed by using the digits 1 to 9 if repetition of digits is not allowed?

How many chords can be drawn through 21 points on a circle?

There are 20 books on Algebra and Calculus in one library. For the greatest number of selections each of which consists of 5 books on each topic. If the possible number of Algebra books are N, then the value N/2 is __________.

$n$ is selected from the set ${1,2,3,………….,100}$ and the number $2_{n}+3_{n}+5_{n}$ is formed. Total number of ways of selecting $n$ so that the formed number is divisible by 4 is equal to $(A)$ 50 $(B)$ 49 $(C)$ 48 $(D)$ None of these.

The total number of divisor of 480 that are of the form $4n+2,n≥0,$ is equal to a. $2$ b. $3$ c. $4$ d. none of these

Find the number of different 8-letter arrangements that can be made from the letters of the word DAUGHTER so that(i) all vowels occur together (ii) all vowels do not occur together.

How many 3-digit numbers can be formed by using the digits 1 to 9 if no digit is repeated?