Is there a row in which all the digits from 0 to 9 appear as the ones digit? Which rows have this property?
Yes, rows 1, 3, 7, and 9 have all digits from 0 to 9 appearing as ones digits.
Step 1: Check row 1 ones digits: 1, 2, 3, 4, 5, 6, 7, 8, 9, 0 — all digits present.
Step 2: Check row 3 ones digits: 3, 6, 9, 2, 5, 8, 1, 4, 7, 0 — all digits present.
Step 3: Check row 7 ones digits: 7, 4, 1, 8, 5, 2, 9, 6, 3, 0 — all digits present.
Step 4: Check row 9 ones digits: 9, 8, 7, 6, 5, 4, 3, 2, 1, 0 — all digits present.
Conclusion: Rows 1, 3, 7, and 9 have complete cycles because 1, 3, 7, and 9 are coprime to 10.
Explanation
The chapter shows that rows 1, 3, 7, and 9 have all digits 0-9 appearing as ones digits. Row 1: 1, 2, 3, 4, 5, 6, 7, 8, 9, 0 (all digits). Row 3: 3, 6, 9, 2, 5, 8, 1, 4, 7, 0 (all digits). Row 7: 7, 4, 1, 8, 5, 2, 9, 6, 3, 0 (all digits). Row 9: 9, 8, 7, 6, 5, 4, 3, 2, 1, 0 (all digits). These rows have complete cycles because 1, 3, 7, and 9 are coprime to 10.
Solution Steps
Step 1: Check row 1 ones digits: 1, 2, 3, 4, 5, 6, 7, 8, 9, 0 - all digits present
Step 2: Check row 3 ones digits: 3, 6, 9, 2, 5, 8, 1, 4, 7, 0 - all digits present
Step 3: Check row 7 ones digits: 7, 4, 1, 8, 5, 2, 9, 6, 3, 0 - all digits present
Step 4: Check row 9 ones digits: 9, 8, 7, 6, 5, 4, 3, 2, 1, 0 - all digits present