Answer:
[tex]S_{32}[/tex] = - 1216
Step-by-step explanation:
The sum to n terms of an arithmetic sequence is
[tex]S_{n}[/tex] = [tex]\frac{n}{2}[/tex] [ 2a₁ + (n - 1)d ]
where a₁ is the first term and d the common difference
Here a₁ = 24 and d = a₂ - a₁ = 20 - 24 = - 4 , then
[tex]S_{32}[/tex] = [tex]\frac{32}{2}[/tex] [ (2 × 24) + (31 × - 4) ]
= 16(48 - 124)
= 16 × - 76
= - 1216