To solve this problem, let's represent the number as \( N \) such that it satisfies the given conditions when divided by 5, 7, and 8. We are given:
To find such an \( N \), we'll apply the method of successive substitutions using the Chinese Remainder Theorem. Accordingly, we find a number \( N \) that satisfies all conditions:
Step 1: Start with the condition \( N \equiv 4 \ (\text{mod} \ 8) \). This implies that \( N = 8a + 4 \).
Step 2: Apply for \( 8a + 4 \equiv 3 \ (\text{mod} \ 7) \):
\(8a + 4 \equiv 3 \ (\text{mod} \ 7)\)
Simplifying, we get \(8a \equiv -1 \equiv 6 \ (\text{mod} \ 7)\) because \(-1 \equiv 6 \) under modulo 7.
\( 8 \equiv 1 \ (\text{mod} \ 7) \), thus:
\(a \equiv 6 \ (\text{mod} \ 7)\)
Therefore, \( a = 7b + 6 \) for some integer \( b \).
Step 3: Substitute back \( a \) in \( N = 8a + 4 \):
\(N = 8(7b + 6) + 4 = 56b + 48 + 4 = 56b + 52\)
Step 4: Apply \( 56b + 52 \equiv 2 \ (\text{mod} \ 5) \):
Simplifying: \(56b + 52 \equiv 2 \ (\text{mod} \ 5) \Rightarrow 56 \equiv 1 \ (\text{mod} \ 5), 52 \equiv 2 \ (\text{mod} \ 5)\)
\( 56b + 52 \equiv b + 2 \equiv 2 \ (\text{mod} \ 5) \Rightarrow b \equiv 0 \ (\text{mod} \ 5) \)
Therefore, \( b = 5c \) for some integer \( c \). Substitute back in the expression for \( N \): \(N = 56(5c) + 52 = 280c + 52.\) Verify with options provided:
Check for \( N = 437 \):
Thus, the correct number that matches all conditions is 437.