A and B can do a piece of work in 45 days and 40 days respectively. They began to do the work together but A leaves after some days and then B completed the remaining part of the work in 23 days. After how many days did A leave the […]

One of the two buses completes a journey of 300 km in 7 hours 30 minutes and the other a journey of 450 km in 10 hours. What is the ratio of their average speeds?