Rudolph's Nose Solution

1. He will need 9 light bulbs.  (There are 3 sets of 8 hours in 24 hours.  Rudolph needs 3 new bulbs for each set of 8 hours. 3 x 3 = 9)

2. Santa will need to spend £11.25.  (9 x 1.25 = 11.25)