A bag contains four red counters and six black counters. A counter is picked at random from the bag and not replaced. A second counter is then picked. Calculate the following probabilities: (a) the...

A bag contains four red counters and six black counters. A counter is picked at random from the bag and not replaced. A second counter is then picked. Calculate the following probabilities: (a) the second counter is red, given that the fi rst is red; (b) both the counters are red; and (c) the counters are of different colours.