Vivek is painting three doors. The doors are numbered 1,2 and 3. Each door is to be painted one colour: either black or gold. One possibility is that door 1 is painted black, door 2 is painted gold, and door 3 is painted gold. In total, how many different ways can the three doors be painted?
(A) 8
(B) 7
(C) 5
(D) 4
(E) 3
Since there are 3 doors and 2 colour choices for each door, there are $2^{3}=8$ ways of painting the three doors.

Using "B" to represent black and "G" to represent gold, these ways are BBB, BBG, BGB, BGG, GBB, GBG, GGB, and GGG.

ANSWER: (A)