For the following questions answer them individually
A milling machine has the following two index plates supplied along with the indexing head:
Plate 1: 15, 16,17,18, 19, 20, hole circles
Plate 2: 21,23,27,29,31,33, hole circles
It is proposed to mill a spur gear of 28 teeth using simple indexing method. Which one of the following combinations of index plate and number of revolutions is correct?