The average of 22 numbers is 52. The average of the first 8 num- bers is 48 and the average of next 11 numbers is 54. The 20 th number is 7 less than the 21 st number and 21 st number is 4 more than 22 nd number.What is the average of the 20 th and 22 nd number? (1) 52 (2) 52.5 (3) 53 (4) 53.5