VTMO 2026 - Grade 6 - Final - SET 3 - Self-study Question 4

The six-digit number $\overline{abcdef}$ is divisible by 7. Prove that the six-digit number $\overline{efabcd}$ is also divisible by 7. Here $a$ and $e$ are nonzero digits, as required for the two numbers to have six digits.