The average of thirteen numbers is 40. The average of the first three numbers is 30 and that of the next seven numbers is 50. The 11th number is twice the 12th number and the 12th number is 3 less than the 13th. What is the average of the 11th and 13th numbers?
1
30.375
2
32.563
3
34.873
4
35.543