Raymond B. answered 08/29/20
Math, microeconomics or criminal justice
This is a strange problem. Seemingly a simple 2 equation, 2 unknown algebra problem.
But something goes wrong. Something is odd about this problem.
A+C=35, the total number of tickets sold
8.75A + 11C = $259
Multiply the first equation by 11 to get
11A+11C=385. then subtract the 2nd equation
8.75A+11C=259 to get
2.25A = 385-259= 126, divide by 2.25
A= 126/2.25= 56. That comes out even, no remainder, no partial number, so it looks right, at first.
But check the answer
If A=56, then C=35-56 = -21. That means more adult tickets were purchased than the total number of tickets. It's as if 56 adults bought tickets and 21 children sold tickets to get a grand total sold of 35
Yet, plug in those numbers into the 2nd equation and it works
8.75(56) + 11(-21) = 259
490 -231 = 259
259 = 259
You could graph the two equations and where the two lines intersect would be the solution
A on the y-axis, C on the x-axis, then the point (-21,56) would be where they intersect.
But this may be mixing apples & oranges, as 35 is a pure number, no dollars, while 259 is in dollars. But that's misleading, as we muliply by $11 which makes the units the same.
Looking at it another way. IF A=0 then C= 23+ but not greater than 23 as an integer. to satisfy the 2nd equation, Yet C=35 for the 1st equation. IF C=0, then A = 29+ but not greater than 29 as an integer, yet A=35 to satisfy the 1st equation.
There's no way for Both A and C to be positive, and satisfy both equations.