The third row shows that two pigs and two mice sum to 80. Thus a single pig and a single mouse sum to 40:
pig + mouse = 40.
Looking now at the first row, we see that all four animals sum to 80. Since the pig and mouse together give 40, the remaining two animals must provide the remaining 40.
cow + rooster = 40.
The second row states that a cow and a rooster, plus two pigs, give 90. It must be the case then that two pigs give 50 and consequently, that a single pig is worth 25.
pig = 25.
This is all the information we need to solve the puzzle. The third column is comprised of a pig and a mouse (together worth 40) and an additional single pig (worth 25). Thus the value of fourth column is 65.
Notice that we can go a little further if we wish and determine that a mouse has value 15 (pig plus mouse is 40, with pig equal to 25) and that the sum of symbols in the third column – cow plus rooster (worth 40) and a single mouse (worth 15) – is 55. However, there is not enough information in this puzzle to determine the value of a single cow, a single rooster, or the value of the sum of the first or second column. (This is not surprising since we are told only three pieces of information about four unknown quantities. We have an “under-determined” system.)
There are a number of mathematical techniques for solving puzzles like these. If you are interested in learning some more about this, please click here.
