After transaction coins are distributed as follows:
• Buyer has 1 crown and 1 threepence
• Shopkeeper has 1 half-sovereign, 1 half-crown, 1 sixpence and 1 fourpence
• Friend has 1 double-florin, one florin, 1 shilling and 1 penny

Xpress-Mosel Model

model 'lccoin'

! Description  : Lewis Carroll coin puzzle
! Source       : Wakeling, E., (1995), Rediscovered Lewis Carroll Puzzles, Dover. 
! Date written : Xpress-MP 7/10/99, Mosel 17/4/03
! Written by   : M J Chlond 

  uses 'mmxprs'
  
  parameters
    person = 3
    coin = 10
  end-parameters

  declarations
    P = 1..person
    C = 1..coin
    requ: array(P) of real
    value: array(C) of real
    x: array(C,P) of mpvar
  end-declarations

  requ:= [63,160,85]
  value:= [120,60,48,30,24,12,6,4,3,1]

  any:= x(1,1)

  forall(j in P)
    reqcon(j):= sum(i in C) value(i)*x(i,j) = requ(j)
  forall(i in C)
    useone(i):= sum(j in P) x(i,j) = 1

  forall(i in C, j in P)
    x(i,j) is_binary

  minimise(any)

  forall(i in C) do
    forall(j in P)
      write(getsol(x(i,j)),' ')
    writeln
  end-do
  
end-model