JEE MainMathematicsPermutations and CombinationsMCQ+4 / −1
The number of integers greater than 6,000 that can be formed, using the digits 3, 5, 6, 7 and 8, without repetition, is:
- A120
- B72
- C216
- D192
View written solutionFree
Correct answer: D
-
We need to count integers greater than formed using the digits without repetition.
-
Since the number must be greater than , it can have either:
- digits, or
- digits.
-
Count 4-digit numbers greater than
For a 4-digit number to be greater than , its thousand's digit must be one of .
- Choose the first digit: ways ()
- Choose and arrange the remaining places from the remaining digits:
So, number of such 4-digit numbers is
-
Count 5-digit numbers
Any 5-digit number formed from these digits is automatically greater than .
Number of 5-digit numbers using all digits without repetition:
-
Total numbers
-
Therefore, the required number of integers is
-
Comparison with stored answer
Stored correct answer is D, which corresponds to .
Hence, my derived answer agrees with the stored answer.
More from Permutations and Combinations
- Let A and B be two sets containing 2 elements and 4 elements respectively. The number of subsets of A B having 3 or more elements is :2013 · MCQ
- Let be the number of all possible triangles formed by joining vertices of an n-sided regular polygon. If = 10, then the value of n is :2013 · MCQ
- Assuming the balls to be identical except for difference in colours, the number of ways in which one or more balls can be selected from 10 white, 9 green and 7 black balls is:2012 · MCQ
- Statement - 1: The number of ways of distributing 10 identical balls in 4 distinct boxes such that no box is emply is . Statement - 2: The number of ways of choosing any 3 places from 9 different places is .2011 · MCQ
- These are 10 points in a plane, out of these 6 are collinear, if N is the number of triangles formed by joining these points. then:2011 · MCQ
- There are two urns. Urn A has 3 distinct red balls and urn B has 9 distinct blue balls. From each urn two balls are taken out at random and then transferred to the other. The number of ways in which this can be done is2010 · MCQ
- From 6 different novels and 3 different dictionaries, 4 novels and 1 dictionary are to be selected and arranged in a row on a shelf so that the dictionary is always in the middle. Then the number of such arrangement is :2009 · MCQ
- How many different words can be formed by jumbling the letters in the word MISSISSIPPI in which no two S are adjacent?2008 · MCQ