hi i'm a bit confused on a simple question which i thought i did correct, but the mark scheme has a different answer.

A bag contains a large number of coins:

75% are 10p coins,

25% are 5p coins.

A random sample of 3 coins is drawn from the bag.

Find the sampling distribution for the median of the values of the 3 selected coins

and the answer is:

Median 5: p = (0.25)^3 + 3(0.75)(0.25)^2= 10/64

Median 10:p = (0.75)^3 + 3(0.25)(0.75)^2= 54/64

so basically they are using the case for median 5 with 2 5's or 3 5's, but these are the combinations:

Median 5: (5 5 5) (5 5 10) (10 5 10) (10 5 5)

Median 10: (10 10 10) (5 10 10) (10 10 5) (5 10 5)

why are the combinations i've shown in red used the other way around?