If 7 + y = 4 (mod 8), find the least value of y, 10 \(\leq y \leq 30\)
- 11
-
13
- 19
- 21
The correct answer is: B
Explanation
7 + y = 4 (mod 8)
y = 4 - 7 (mod 8)
y = -3 + 8 (mod 8)
y = 5 + 8 (mod 8)
y = 13