The number of seven digits odd numbers, that can be formed using all the seven digits $1,2,2,2,3,3,5$ is_______
Correct Answer: 240
Approach Solution - 1
Digits are 1,2,2,2,3,3,5
If unit digit 5 , then total numbers \(=\frac{6!}{3!2!}=60\)
If unit digit 3 , then total numbers \(=\frac{6!}{3!} =120\)
If unit digit 1 , then total numbers \(=\frac{6!}{3!2!}=60\)
∴ total numbers =60+60+120=240
So , the correct answer is 240
Approach Solution -2
Top JEE Main Mathematics Questions
- The value of is
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Top JEE Main Questions
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Concepts Used:
Complex Numbers and Quadratic Equations
Complex Number: Any number that is formed as a+ib is called a complex number. For example: 9+3i,7+8i are complex numbers. Here i = -1. With this we can say that i² = 1. So, for every equation which does not have a real solution we can use i = -1.
Quadratic equation: A polynomial that has two roots or is of the degree 2 is called a quadratic equation. The general form of a quadratic equation is y=ax²+bx+c. Here a≠0, b and c are the real numbers.
