Whiteboard problem for Friday and the weekend

Yes, the problem below is solvable.  But, it requires your mathematical skill, your wits, cunning and a little persistence.  Oh! That just happens to be my definition of numeracy.

The problem is stolen from Stylianides and Stylianides (2015) which they took, and slightly modified, from a teacher training text book (Philippou and Christou, 1995, p. 132).

Remember - it is solvable. You can do it and your children can do it. It just takes 'numeracy'.

By the way - 'product' in maths speak, means what number you get after multiplying.  'Sum' means what you get when you add. 

I'll post the answer and explanation on Saturday.

You got this.

Update:

I hope you managed to give it a go.  For those who did, you will have noticed that the problem required deductive, 'common sense' reasoning.  When used with teachers, many teachers note that it does not look like a maths problem.

Helen: I thought it was interesting that we used non-numerical clues to find the answer. It was frustrating to work it out at first but made sense in the end. 

Laney: It made me realise that my initial thoughts about the problem were completely wrong and this problem was possible. I now understand that problems that seem impossible or seem to have irrelevant parts might actually be able to be solved. Before dismissing any problem, put some real effort into it and think about it in numerous ways.

Solution here.