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
- 8x + 5 = 0
- 8(x + 5) = x
- 8x = x + 5
- None of these
اس سوال کو وضاحت کے ساتھ پڑھیں
- (x+5)(x−4)/(x−2)(x+2)
- x+5/x+2
- x−4/x−2
- x+5/x−2
اس سوال کو وضاحت کے ساتھ پڑھیں
- 20
- 25
- 30
- 35
اس سوال کو وضاحت کے ساتھ پڑھیں
