Problem
NT-B1-M10-P023 When \(R_a\mid R_b\)
#23
★★★★☆ Level 4 of 5
Prove that if \(R_a\mid R_b\), then \(a\mid b\).
Write \(b=qa+r\), \(0\le r
Since \(10^a\equiv1\pmod{R_a}\), for \(b=qa+r\), \(0\le r
Strong problem: carefully proves a known fact.