Admission to the zoo costs $15 for adults and $5 for kids. The total bill for your entire extended family was $390. This scenario can be modeled by the equation 15a + 5k = 390. Which of the following is not a possible combination of adults and kids?

Question

anonymous · Answer

which of the following what?

anonymous · Answer

9 adults and 51 kids 

 17 adults and 27 kids 

 21 adults and 15 kids 

 23 adults and 0 kids

oblivious · Answer

well, you can just plug in each set and see if the equality holds true, but it is a little easier to first solve for one of the variables ex:
k=78-3a
Plugging in each answer we see this holds true in every case except the last case. If there really were no kids there would have needed to be 26 adults for the bill to be 390

anonymous · Answer

thankkyouu  !