As I’m sure you remember, this week’s puzzle looked like this, and you were tasked with working out what number should fill in the square with the question mark:
Solution after the break!
Okay so, the first step was to realise that you could place a number 2 on the bottom row – this will be useful. (You could also put in a 32, but since it’s in the corner it won’t help us.) So now your pyramid looks something like this:
[EDIT: Reader Xbalanque has come up with a better solution than myself to solve this puzzle from here on, but feel free to follow whichever solution you prefer.]
Truthfully, the next step requires a lot of educated guesswork.
You need to find numbers which fit the gaps in the second layer up (between 46 and 28) that add up to 30 (the number above) and the only real way to get them is by methodically trying pairs until something works. Of course, you do know that one number must be bigger than 14, and that the other is bigger than 2.
So you might start with, say, 15 and 15, but this clearly doesn’t work because 14+1 = 15 but 1+2 is definitely not equal to 15. So you can work from there. Eventually you’ll see that 21 and 9 fit, making the middle-bottom square a 7. Now you have this:
All that’s left now is to simply work up the pyramid, filling in 67 and then, of course, 97 in the question mark spot (those of you who guessed 67 just needed to go a little further).
See you next week for the next puzzle!