Question 9
The two-digit numbers $\overline{ab}$ and $\overline{ba}$ both leave remainder 1 on division by 7. Find $\overline{ab}\times\overline{ba}$. Original choices: (A) 2156; (B) 2234; (C) 2668; (D) 3132; (E) 3505.
Source wording does not say that the two digits are different. Preserve that wording: explain whether the product is uniquely determined, and discuss the original choices. This item is assessed manually.
Source wording does not say that the two digits are different. Preserve that wording: explain whether the product is uniquely determined, and discuss the original choices. This item is assessed manually.