A bag contains n counters. One counter is blue and the rest are red.
Two counters are taken at random from the bag.
a) Express, in terms of n, the probability that a counter of each colour is taken.
Give your answer as a fraction in its simplest form.

Anut store normally sells cashews for? $4.00 per pound and peanuts for? $1.50 per pound. but at the end of the month the peanuts had not sold? well, so, in order to sell 40 pounds of? peanuts, the manager decided to mix the 40 pounds of peanuts with some cashews and sell the mixture for $2.00 per pound. how many pounds of cashews should be mixed with the peanuts to ensure no change in the? profit?