Final answer:
Sara can make 1 necklace with 4 yards of chain because each necklace requires 3 yards. Therefore, only models that show Sara can make 1 necklace are correct; any model indicating more than 1 necklace is incorrect.
Step-by-step explanation:
The question is asking about a mathematical problem related to division and modelling a real-life situation. Sara needs to make necklaces using chains that she buys by the yard. She uses 3 yards of chain for each necklace and wants to know how many necklaces she can make with 4 yards of chain. A model that could not be used to represent this situation is anything that implies she can make more than one necklace with the 4 yards of chain, since she would need at least 3 yards for one necklace and would have 1 yard left, which is not enough for another complete necklace.
To determine how many necklaces can be made, we divide the total yards of chain Sara has by the amount required for one necklace. 4 yards divided by 3 yards per necklace equals approximately 1.33, which means Sara can only make 1 necklace, because she cannot make a fraction of a necklace. Therefore, any model suggesting you can make 2 or more necklaces with 4 yards of chain would be incorrect.