Challenges: Final Friday Fix: December 2018 Challenge

Welcome to the December Final Friday Fix! It clearly appears that we’ve been doing more training and less consulting work as the year comes to a close, as our challenge problem has again been inspired from a question on Reddit.

This month, we are posed with an interesting problem that is easy to explain, but more difficult to test – given a series of numbers, and a target sum, can you get Excel to tell you which combination of numbers will result in the sum being achieved?

For example, with a target of 10 and the numbers:

… we should expect to see the results of 9 + 1, 7 + 3, 7 + 2 + 1 and 5 + 2 + 3 (in no particular order).

A couple of rules:

• No macros / VBA
• No array (Ctrl + Shift + Enter) functions
• No Solver or other iterative tools (i.e. no circular references)
• Feel free to use Power Query if you think it will help.

It’s deceptively easy, but gets exponentially harder as you include more numbers to check. Think you’re up to the challenge? We’ve got an example file here that you can use to start you off. Let us know what your solution is at contact@sumproduct.com, but we’ll give you our sample answer on Monday as usual. Happy holidays!