Use CountChange defined in "Wellin - Essential of Programming" Page 117?

Questions
1

Why does my function CountChange not work the same way, Wellin says it does on page 117 of his book Essential of Programming…?

CountChange is CountChange[coins_Llist] := Total[coins /. {p -> .01, n -> .05, d -> .10, q -> .25}]
CountChange[{p, q, q, d, d, p, q, q, d, d}]

Why do I not receive output of “1.42”. Please see attach

Paged 117 Essentials Wellin.nb (77.1 KB)

2

His In[1] on page 116 is

coins={p,p,q,n,d,d,p,q,q,p}

Compare with your In[1].

3

The function should be defined as:

CountCoins[coins_List] (*you have defined the pattern _Head wrongly. First letter of the "list" should be capital*)