If a, b are positive integers, where in the (modulo 7) with the multiplication operation, then inverse of 3 in the group is?
- 4
- 5
- 3
- None of these
Explanation
To find the inverse of 3 in modulo 7, we need to find a number x such that:
3x ≡ 1 (mod 7)
We can try multiplying 3 by each number from 1 to 6:
3 × 1 = 3
3 × 2 = 6
3 × 3 = 9 ≡ 2 (mod 7)
3 × 4 = 12 ≡ 5 (mod 7)
3 × 5 = 15 ≡ 1 (mod 7)
So, the inverse of 3 in modulo 7 is 5.
Related MCQs
- Odd function
- Even function
- Constant symmetric form
- None of these
اس سوال کو وضاحت کے ساتھ پڑھیں
- Factoring the polynomial
- Finding the derivative
- Substituting the value of x
- None of these
اس سوال کو وضاحت کے ساتھ پڑھیں
- x = 2, −1/2
- x = 1, −2
- x = 3, −1
- None of these
اس سوال کو وضاحت کے ساتھ پڑھیں
- Commutative
- Associative
- Distributive
- None of these