A mini-van crosses two people walking at the speed of 4.8 kmph and 6 kmph in the same direction as that in which the mini-van is heading in 4.5 s and 9 s, respectively. What is the length of the mini-van?
In a certain code language, '-' represents '+', '+' represents 'x', 'x' represents '÷' and '÷' represents '-'. Find out the answer to the following question.