A new bag of cat food weighs 18 pounds. At the end of each day, 0.5 pounds of food is removed to feed the cats. Find the 30th term, and explain what it represents.

Answer:
[tex]30^{th}[/tex] term = 3.5 pounds
[tex]30^{th}[/tex] term represents the amount of dog food at the beginning of the [tex]30^{th}[/tex] day.
Step-by-step explanation:
1st term = [tex]18[/tex] ⇒[tex]18-0*0.5[/tex]
2nd term = [tex]18-0.5[/tex] ⇒[tex]18-1*0.5[/tex]
3rd term = [tex]18-0.5-0.5[/tex] ⇒[tex]18-2*0.5[/tex]
It will follow the same pattern until the value is 0.
So we can observe that in the [tex]1^{st}[/tex] term there are no "0.5" terms.
In the [tex]2^{nd}[/tex] term we have 1 "0.5" term and in the [tex]3^{rd}[/tex] term we have 2 "0.5" terms.
It is clear that the number of "0.5" terms are always 1 less than the term that we are in.
So we can write the term for the [tex]30^{th}[/tex] term as;
[tex]18-(30-1)*0.5[/tex]
[tex]18-29*0.5[/tex]
=3.5 pounds
[tex]1^{st}[/tex] term represents the amount of dog food at the beginning of the [tex]1^{st}[/tex] day.
[tex]2^{nd}[/tex] term represents the amount of dog food at the beginning of the [tex]2^{nd}[/tex] day.
Same with the [tex]3^{rd}[/tex] term.
So we can say that [tex]30^{th}[/tex] term represents the amount of dog food at the beginning of the [tex]30^{th}[/tex] day.