- A175
- B162
- C160
- D180
View written solutionFree
Correct answer: D
-
Identify the digits and their positions
The digits are:
Total digits , so each number formed has places.
Odd digits are: There are odd digits.
Even places among positions are: So there are even positions.
-
Condition: odd digits occupy even places
This means all the odd digits must be placed in even positions only.
So first, choose of the even positions for these odd digits:
-
Arrange the odd digits in the chosen even positions
We must arrange in those selected places.
Number of distinct arrangements:
So, total ways to place odd digits:
-
Arrange the remaining even digits in the remaining places
After placing the odd digits, the remaining digits are: These occupy the remaining positions.
Number of distinct arrangements of these digits:
-
Total number of required numbers
Multiply the two independent counts:
-
Check options
The correct value is:
Hence, the correct option is D.
More from Permutations and Combinations
- The number of four-digit numbers strictly greater than 4321 that can be formed using the digits 0,1,2,3,4,5 (repetition of digits is allowed) is :2019 · MCQ
- A committee of 11 members is to be formed from 8 males and 5 females. If m is the number of ways the committee is formed with at least 6 males and n is the number of ways the committee is formed with at least 3 females, then :2019 · MCQ
- Consider a class of 5 girls and 7 boys. The number of different teams consisting of 2 girls and 3 boys that can be formed from this class, if there are two specific boys A and B, who refuse to be the members of the same team, is :2019 · MCQ
- The number of natural numbers less than 7,000 which can be formed by using the digits 0, 1, 3, 7, 9 (repitition of digits allowed) is equal to :2019 · MCQ
- Let S be the set of all triangles in the xy-plane, each having one vertex at the origin and the other two vertices lie on coordinate axes with integral coordinates. If each triangle in S has area 50 sq. units, then the number of elements…2019 · MCQ
- The number of 6 digit numbers that can be formed using the digits 0, 1, 2, 5, 7 and 9 which are divisible by 11 and no digit is repeated is :2019 · MCQ
- Suppose that 20 pillars of the same height have been erected along the boundary of a circular stadium. If the top of each pillar has been connected by beams with the top of all its non-adjacent pillars, then the total number of beams is :2019 · MCQ
- If then K is equal to :2019 · MCQ