Respuesta :
Answer:
The height will be 79 inches after 3 weeks.
Step-by-step explanation:
We are given that A pile of newspapers in Ms McGrath's art class was [tex]17 \frac{3}{4} = \frac{71}{4}[/tex]inches high
We are also given that each Consecutive week,for the next 5 weeks,the height of the pile of newspapers increased by [tex]8 \frac{7}{12} =\frac{103}{12}[/tex]inches
Now we are supposed to find What was the height ,in inches,of the pile after 3 weeks?
This situation is an AP
a = [tex]\frac{71}{4}[/tex]inches high
d =common difference = [tex]\frac{103}{12}[/tex]inches
Formula of sum of first n terms = [tex]S_n=\frac{n}{2}(2a+(n-1)d)[/tex]
[tex]S_{3}=\frac{3}{2}(2(\frac{71}{4})+(3-1)(\frac{103}{12}))[/tex]
[tex]S_{3}=\frac{3}{2}(2(\frac{71}{4})+(3-1)(\frac{103}{12}))[/tex]
[tex]a_{3}=79[/tex]
Hence the height will be 79 inches after 3 weeks.
