The average of the numbers of a set P, consisting of 20 numbers, is 20. There are 20 numbers in another set Q = {ai : i = 1, 2, 3, .20}. Now, all the 20 numbers, starting from a1 to a20, in that order, are shifted from the set Q to the set P, one after the other. During the process of shifting, it was observed that when the number ai was shifted from set Q to set P, the average of the numbers of set P increased by bi, where bi+1 - bi = 1, for 1 £ i £ 19. If

b1 = 2, what is the average of the original 20 numbers of set Q?

In Kiran's opinion, his weight is greater than 65 kg but less than 72 kg. His brother does not agree with Kiran and he thinks that Kiran's weight is greater than 60 kg but less than 70 kg. His mother's view is that his weight cannot be greater than 68 kg. If all are them are correct in their estimation, what is the average of different probable weights of Kiran?

In a survey conducted to find out the readership of three newspapers A, B and C, it was found that the number of people who read newspaper A is at least 20 and at most 40, the number of people who read newspaper B is at least 50 and at most 70, the number of people who read newspaper C is at least 70 and at most 83. It was also found that 8 people read all the three newspapers and 85 people read at least two of the three newspapers. Find the minimum number of people who read both A and B but not C