Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main 202310 AprilMorning Shift
Exam
JEE Main
Year
2023
Date
10 April
Shift
Morning Shift
Subject
Mathematics
Chapter
Permutation and Combination

JEE Main 2023 · 10 April · Morning Shift · Mathematics · Permutation and Combination

The number of permutations, of the digits 1, 2, 3, , 7 without...

The number of permutations, of the digits 1,2,3,…,71, 2, 3, \ldots , 7 without repetition, which neither contain the string 153153 nor the string 24672467, is _______ .

Correct answer

0

Step-by-step solution

Given,

The number 1,2,3,....,71, 2, 3, . . . . , 7

Now total numbers of 77 digit number will be 7!7 ! without repetition,

Now total numbers which contain string 154154 will be 5!5 !

Total numbers which contain string 23672367 will be 4!4 !

And number which contain both string 2367 and 1542367 \text{ and } 154 will be 22

So, total number which does not contain string 154154 or 23672367 will be 7!−(5!+4!−2)7 ! - \left(5 ! + 4 ! - 2\right)

=5040−(120+24−2)= 5040 - \left(120 + 24 - 2\right)

=5040−142=4898= 5040 - 142 = 4898

Hence this is the required answer.

Practice Permutation and Combination on Quantrex Academy →

More from Permutation and Combination

All Permutation and Combination questions Full Permutation and Combination list Permutation and Combination JEE Maths PYQsJEE Mathematics PYQs All JEE Main PYQs