Answer : D) {4R, 4B, 4C, 5R, 5B, 5C, 6R, 6B, 6C}
Step-to step explanation:
Given : Choices for phone models= 4, 5, and 6 ( 3 choices)
Choices for protective case = red (R), blue (B), or camo (C) ( 3 choices)
Number of different refurbished phone can be made = ( Choices for phone models) x (Choices for protective case)
= 3 x 3 = 9 choices
Therefore , the number of different choices he has = 9
Since only option D has all 9 choices (each phone models pair with each kin of protective case)
Hence, all the different choices he has = {4R, 4B, 4C, 5R, 5B, 5C, 6R, 6B, 6C}
