# Talk

## Substitution (Simultaneous Equation) Puzzles

(5 Posts)
TheLovelyBoots Thu 18-Dec-14 14:08:16

I found this puzzle on the NLCS 11+ sample paper. Can you suggest where I might find more? (I couldn't copy/paste, sigh)

heart triangle smileyface triangle = 99
smileyface triangle triangle heart = 99
heart smileyface heart smileyface = 154
triangle heart smileyface triangle = 99
= = = =
142 99 ? 99

It sorta helps to assume that the numbers are all being added. Is that right? Then the problem makes sense. Comparing two pairs of different rows and columns give
smiley = triangle +12;
heart = triangle + 43;
Then writing any one of the 99 rows all in terms of triangles gives triangle = 11. The rest follows, e.g. smiley = 23 etc.

TheLovelyBoots Thu 18-Dec-14 21:45:45

That's right. My question is where I might find a worksheet of such puzzles? I can find only very few one-offs.

noblegiraffe Thu 18-Dec-14 23:21:55

https://www.tes.co.uk/teaching-resource/Simultaneous-Equations-Puzzles-3006908/

This is an excel spreadsheet which will let you generate your own puzzles of this type

You'll need to create a TES account first though.