Barry has 4 wooden identically shaped and sized blocks. 2 are blue, 1 is red and 1 is green. How many distinct ways can barry arrange the 4 blocks in a row? Barry's friend Billie is colour-blind and cannot distinguish between red and green. How many of Barry's distinct arrangements would Billie see different?

Step-by-step explanation:

Distinct ways in which Barry can arrange the wooden shaped blocks is calculated from the permutation expression

4 permutation 3 =

P (n, r) = P (4,3) = 4! : (4-3) ! = 24

Billie's distinct ways of seeing the arrangement would be 4 permutation 2

P (n, r) = P (4,2) = 4! : (4-2) ! = 12

The distinct arrangement Billie would see is P (n, r) = P (4,2) = 4! : (4-2) ! = 12

Step-by-step explanation:

From the question, we recall the following:

Blue = 2, red = 1 green = 1

The way this can be solved for which Barry can arrange the wooden shaped blocks is applying the method called permutation

So,

4 permutation 3 = P (n, r) = P (4,3) = 4! : (4-3) ! = 24

The ways Billie's would see the permutation arrangement is 4 permutation 2

With the expression given as

P (n, r) = P (4,2) = 4! : (4-2) ! = 12