A and B are standing at place "P". They start moving in the opposite directions at the speed of 5 Kmph and 4 Kmph respectively. What will be the distance between them after 3 hours?
A man has some hens and some cows. If the total number of heads of hens and cows together is 50 and the nunber of feet of hens and cows together is 142, then the number of cows is