EASY
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IMPORTANT
Earn 100

The number of square matrices of order with entries from the set , such that the sum of all the elements in each row is and the sum of all the elements in each column is also , is
(a)
(b)
(c)
(d)

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Important Questions on Permutation and Combination
HARD
JEE Main
IMPORTANT
Let . The number of non-empty subsets of that have the sum of all elements a multiple of , is _____ .

HARD
JEE Main
IMPORTANT
Let and be distinct integers where and . Then, the number of ways of choosing and , such that is divisible by , is _____ .

EASY
JEE Main
IMPORTANT
The number of numbers, strictly between and can be formed using the digits without repetition, is

EASY
JEE Main
IMPORTANT
is equal to

MEDIUM
JEE Main
IMPORTANT
Suppose Anil's mother wants to give whole fruits to Anil from a basket of red apples, white apples and oranges. If in the selected fruits, at least orange, at least one red apple and at least one white apple must be given, then the number of ways, Anil's mother can offer fruits to Anil is _____ .

EASY
JEE Main
IMPORTANT
If all the six digit numbers with are arranged in the increasing order, then the sum of the digits in the number is _______.

EASY
JEE Main
IMPORTANT
Five digit numbers are formed using the digits with repetitions and are written in descending order with serial numbers. For example, the number has serial number . Then the serial number of is

HARD
JEE Main
IMPORTANT
The letters of the word OUGHT are written in all possible ways and these words are arranged as in a dictionary, in a series. Then the serial number of the word TOUGH is :
