Permutations and Combinations · Mathematics · NDA

What is the sum of all four-digit numbers formed by using all digits 0, 1, 4, 5 without repetition of digits?

A man has 7 relatives (4 women and 3 men). His wife also has 7 relatives (3 women and 4 men). In how many ways can they invite 3 women and 3 men so th...

A triangle $PQR$ is such that 3 points lie on the side $PQ$, 4 points on $QR$ and 5 points on $RP$ respectively. Triangles are constructed using these...

If $26! = n8^k$, where $k$ and $n$ are positive integers, then what is the maximum value of $k$?

How many four-digit natural numbers are there such that all of the digits are even?

Four digit numbers are formed by using the digits 1, 2, 3, 5 without repetition of digits. How many of them are divisible by 4?

What is the number of different matrices, each having 4 entries that can be formed using 1, 2, 3, 4 (repetition is allowed)?

If 1! + 3! + 5! + 7! + ... + 199! is divided by 24, what is the remainder?

What is the maximum number of points of intersection of 10 circles?

If H is the Harmonic Mean of three numbers 10C4, 10C5, and 10C6, then what is the value of $\frac{270}{H}$ ?...

 What is the number of 6-digit numbers that can be formed only by using 0, 1, 2, 3, 4 and 5 (each once); and divisible by 6 ? 

Consider the following statements : 1. (25)! + 1 is divisible by 26 2. (6)! + 1 is divisible by 7 Which of the above statements is/are correct ?&nb...

m parallel lines cut n parallel lines giving rise to 60 parallelograms. What is the value of (m + n) ? 

Let x be the number of permutations of the word ‘PERMUTATIONS’ and y be the number of permutations of the word ‘COMBINATIONS’. Which one of the follow...

5-digit numbers are formed using the digits 0, 1, 2, 4, 5 without repetition. What is the percentage of numbers which are greater than 50,000 ?

If the sum S is divided by 8, what is the remainder ?  

If the sum S is divided by 60, what is the remainder ?