A Problem "Noah's Ark"

This problem is one that I was shown to at COABE a couple of years ago that still has me bamboozled. So, I am posting it here to learn from you all strategies for success.

Math of Noah's Ark


I see lots of these "systems of equations with images instead of variables" online and since it's not written in traditional math language, the authors get to play games with assumptions... 

I see five variabls and four equations.   This makes me wonder if there is a single solution. I'll come back to this ;) 

Hi Susan,

Aren't we asked how many seals plus one bear equal six zebras? Your point is a great one as too many times our students do get caught up in extraneous information. 

I've tried to assign a number value to each animal. No luck yet!

Steve Schmidt

Moderator, LINCS Reading and Writing CoP