UB001
Jack has 24 clients and he wants to use color coding to identify each client. If a single color or two different colors or three different colors can represent a client code, what is the minimum number of colors needed for the coding? Assume that changing the color order within a combination of two or three does not produce different codes.
A. 4
B. 5
C. 6
D. 12
E. 24
In this question, we can use Combination and the answer options as minimum number of colors
When you start with A=4
No of ways you can select 1 color out of 4 will be = 4
No of ways you can select 2 color out of 4 will be = 4C2 = 6
No of ways you can select 3 color out of 4 will be = 4
Giving total as 14 which is less than 24(Total number of clients)
Now you can take the number of colors = 5
No of ways you can select 1 color out of 5 will be = 5
No of ways you can select 2 color out of 5 will be = 5C2 = 10
No of ways you can select 3 color out of 5 will be = 5C3 = 10
Giving total as 25 which is more than 24(Total number of clients)
Thereby satisfying our condition and giving the answer as B
Correct Answer B.