A person complete his journey in 10 hours by car. For the first half of the distance he drives at the speed of 5 kmh"1 and for the second half he drives at speed of .15 kmh"1. What is the total distance ?
'A' and ' B ' can do a work in 20 and 30 days respectively. They began the work together, but 'A left after some time and ' B ' finished the remaining work in 5 days. Then what is the number of days after which 'A' left ?