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Permutations and Combinations

JEE Main 2025 (Online) 3rd April Morning ShiftNumericalEasy📈 Topic in 12% papers+4
Ques. 1JEE Main 2025, 3 April (Morning Shift)

If the number of seven-digit numbers, such that the sum of their digits is even, is m n 10n; m, n \1, 2, 3, , 9\, then m + n is equal to

Answer

14

Solution

The first digit can be chosen in 9 ways (1 to 9) and the 2nd to 6th digits in 105 ways.

For any choice of the first six digits, exactly 5 of the 10 possible last digits make the sum even, so the

required number = 9 105 5 = 45 105

m n 10n = 9 5 105

which gives n = 5, m = 9 (the only choice with m, n \1, , 9\).

m + n = 14

Answer: 14

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Ques. 2JEE Main 2025, 3 April (Evening Shift)

Line L1 of slope 2 and line L2 of slope 12 intersect at the origin O. In the first quadrant, P1, P2, , P12 are 12 points on line L1 and Q1, Q2, , Q9 are 9 points on line L2. Then the total number of triangles, that can be formed having vertices at three of the 22 points O, P1, P2, , P12, Q1, Q2, , Q9, is:

  1. 1026
  2. 1188
  3. 1134
  4. 1080
Ques. 3JEE Main 2025, 2 April (Morning Shift)

The largest n N such that 3n divides 50 ! is :

  1. 22
  2. 20
  3. 21
  4. 23
Ques. 4JEE Main 2025, 2 April (Morning Shift)

The number of sequences of ten terms, whose terms are either 0 or 1 or 2, that contain exactly five 1s and exactly three 2s, is equal to :

  1. 360
  2. 2520
  3. 1820
  4. 45
Ques. 5JEE Main 2025, 2 April (Evening Shift)

The number of ways, in which the letters A, B, C, D, E can be placed in the 8 boxes of the figure below so that no row remains empty and at most one letter can be placed in a box, is : [figure]

  1. 5880
  2. 840
  3. 960
  4. 5760
Ques. 6JEE Main 2025, 29 January (Morning Shift)

Let P be the set of seven digit numbers with sum of their digits equal to 11. If the numbers in P are formed by using the digits 1, 2 and 3 only, then the number of elements in the set P is :

  1. 164
  2. 158
  3. 161
  4. 173
Ques. 7JEE Main 2025, 29 January (Morning Shift)

The number of 6-letter words, with or without meaning, that can be formed using the letters of the word MATHS such that any letter that appears in the word must appear at least twice, is .

Ques. 8JEE Main 2025, 29 January (Evening Shift)

If all the words with or without meaning made using all the letters of the word "KANPUR" are arranged as in a dictionary, then the word at 440th position in this arrangement is :

  1. PRNAKU
  2. PRKAUN
  3. PRKANU
  4. PRNAUK
Ques. 9JEE Main 2025, 28 January (Morning Shift)

Let nCr-1 = 28, nCr = 56 and nCr+1 = 70. Let A(4 t, 4 t), B(2 t, -2 t) and C (3r - n, r2 - n - 1 ) be the vertices of a triangle ABC, where t is a parameter. If (3x - 1)2 + (3y)2 = , is the locus of the centroid of triangle ABC, then equals

  1. 18
  2. 8
  3. 20
  4. 6
Ques. 10JEE Main 2025, 28 January (Morning Shift)

The number of different 5 digit numbers greater than 50000 that can be formed using the digits 0, 1, 2, 3, 4, 5, 6, 7, such that the sum of their first and last digits should not be more than 8, is

  1. 5720
  2. 5719
  3. 4608
  4. 4607
Ques. 11JEE Main 2025, 28 January (Evening Shift)

The number of natural numbers, between 212 and 999, such that the sum of their digits is 15, is .

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