A jewellery company makes rings (R) and necklaces (N).

The resources available to the company have been analysed and two constraints have been identified:

Labour time 3R + 2N ≤ 2,400 hours
Machine time 0·5R + 0·4N ≤ 410 hours

The management accountant has used linear programming to determine that R = 500 and N = 400.

Which of the following is/are slack resources?

(1) Labour time available
(2) Machine time available

A   1 only
B   2 only
C   Both 1 and 2
D   Neither 1 nor 2