A train 110 metres long is running with a speed of 60 kmph . In what time will it pass a man who is running at 6 kmph in the direction opposite to that in which the train is going ?
In a bag the ratio of red balls to green balls is 4 : 9. If 6 more green balls were added to the bag, the ratio of red balls to green balls would become 1 : 3. How many red balls are there in the bag?