If 7 + y = 4 (mod 8), find the least value of y, 10 \(\leq y \leq 30\)
A
11
B
13
C
19
D
21
Verified Correct Answer: B.
Step-by-Step Mathematical Solution
7 + y = 4 (mod 8)
y = 4 - 7 (mod 8)
y = -3 + 8 (mod 8)
y = 5 + 8 (mod 8)
y = 13
Source: Myschool Past Questions Archive (Record #57102)