The time taken to drill a hole of diameter 25 mm in a 30 mm thick steel plate with a feed of 1 mm/rev and the drill spindle speed being 60 rpm is _________ seconds.

The time taken to drill a hole of diameter 25 mm in a 30 mm thick stee

1.	The time taken to drill a hole of diameter 25 mm in a 30 mm thick steel plate with a feed of 1 mm/rev and the drill spindle speed being 60 rpm is _________ seconds.
A.	20
B.	30
C.	40
D.	50
Answer» C. 40