Taking any two points on the curve from 12 to 24 seconds.
Let, two points are P( 12, 8) and Q( 24, 0).
Now , acceleration is given by :
[tex]a=\dfrac{\Delta v}{\Delta t}=\text{Slope of v-t curve}[/tex]
Now , slope
[tex]m=\dfrac{0-8}{24-12}\\\\m=-\dfrac{8}{12}\\\\m=-\dfrac{2}{3}[/tex]
Therefore, average acceleration from 12 to 24 seconds is [tex]-\dfrac{2}{3}[/tex] .
Hence, this is the required solution.
