Latest Elitmus Aptitude Question SOLUTION: number of ways by which 4digit no made where aless than b,bless than c,c less than d where all lies between 1 to 9

• Placement Papers
• /
• Elitmus
• /
• Numerical Ability
• /
• Permutation and Combination

Elitmus Question Papers:

(#M40157506) ELITMUS Numerical Ability question p&c Keep an EYE

number of ways by which 4digit no made where aless than b,bless than c,c less than d where all lies between 1 to 9

Asked In Elitmus SHUBHAM (7 years ago)

Unsolved Read Solution (4)

Is this Puzzle helpful?   (2)   (1) Submit Your Solution Permutation and Combination

Read Solution (4) :

Raghvendra Singh  (7 years ago)

we have to make 4 digit number
in which the format is d> c > b > a
__ __ __ __

1st position can be filled by 6 digits(9, 8, 7, 6, 5, 4)
2nd position can be filled by 6 digits(8, 7, 6, 5, 4, 3)
3rd position can be filled by 6 digits(7, 6, 5, 4, 3, 2)
4th position can be filled by 6 digits(6, 5, 4, 3, 2, 1)

hence every place can be filled by 6 digits,
6* 6* 6* 6 = 1296

Is this solution Helpfull? Yes (6) | No (4)  

Subrata Dutta  (7 years ago)

the correct answer is 126
there are 9 digits to select from 1,2,3,4,5,6,7,8,9
now we have to form 4 digit number .So the total number of selection of 4 digit number is C(9,4).
Now within any selection there is only one possible way to arrange the digits otherwise condition is not satisfied if the digits are arranged.
So the answer is given as C(9,4)*1 =126

Is this solution Helpfull? Yes (4) | No (4)  

Sourav bibhor  (7 years ago)

b c d a
9 8 7 6-1way
8 7 6 5-+1
7 6 5 4-+1
6 5 4 3 -+1
5 4 3 2 -+1
4 3 2 1 -+1
------
6 ways

Is this solution Helpfull? Yes (1) | No (9)  

rajat  (7 years ago)

means a

Is this solution Helpfull? Yes | No (1)  

Please Login to Read Solution.