Substance A and B have retention times of 16.4 and 17.63 mins, respectively on a 30 cm column. An unretained species passes through the column at 1.3...

Substance A and B have retention times of 16.4 and 17.63 mins, respectively on a 30 cm column. An unretained species passes through the column at 1.3 mins. The base of the peak widths for A and B are 1.11 and 1.21 respectively.

1. What is the Plate height if I calculated the average number of plates is 3445?
2. I had a resolution of 1.06, what is the required length of column to achieve a resolution of 1.5
3. Finally the time to elute substance B on the longer column.