Answers to last month’s puzzle:  The census taker:  Write out all possible combinations that add to 13. Out of the 8 total possible age combinations, there are only 2 that when multiplied equal 36. When the lady said her eldest was upstairs asleep, that implied that he was not a twin. Therefore, the ages must be 2, 2 and 9, not 1, 6 and 6.

This month: Replace all the Xs with digits to make this division valid.  It’s easier than you think.