\[\boxed{\text{149.}\text{\ }\text{ОК\ ГДЗ\ -\ домашка\ на\ 5}}\]
\[\textbf{а)}\ 1,5\ с;\ \ \ \]
\[\textbf{б)}\ 2,5\ с;\ \ \ \]
\[\textbf{в)}\ 31,25\ м;\ \ \ \ \]
\[\textbf{г)}\ 4\ с.\]