[tex]4.\text{ }8C2=28[/tex][tex]\begin{gathered} 5.\text{ they reached }\frac{4}{5} \\ \text{they n}eed\text{ to go}\Rightarrow1-\frac{4}{5}=\frac{1}{5} \\ 1\text{ mile =}\frac{4}{5}\Rightarrow\frac{1}{5}=\frac{1}{4\text{ }}mile \end{gathered}[/tex][tex]\begin{gathered} 6.\text{ a=6, d=3} \\ a_8=a+(n-1)d \\ a_8=6+(8-1)3 \\ a_8=6+21 \\ a_8=27 \end{gathered}[/tex]
