\[\boxed{\text{120\ (120).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[\textbf{а)}\ 1,5\ с;\ \ \ \]
\[\textbf{б)}\ 2,5\ с;\ \ \ \]
\[\textbf{в)}\ 31,25\ м;\ \ \ \ \]
\[\textbf{г)}\ 4\ с.\]