The amount of crew members is any of the following
101 or 303 or 707 or 1717 or 3737 or 5151 or 11211 or 12019 or 26159 or 45481 or 63529 90962 or 190587 or 444703 or 500291 or 1000582
Some logical thinking:
C is either 3 or 4, since C = 2 would make the captain 8 years old (VERY young to be a grandfather, let alone have a licence to captain an ocean-going vessel) and C = 5 would let the captain be 125. Way too old to be alive.
All other variables have a known domain:
X = 1:31 (technically, months can be shorter, but the final result is identical if we limit ourselves to X = 1:28).
Y = 1:12.
Z = 1:100.
U = 2:10, since the question clearly talks about propellors (plural).
V = 2:10
Brute force! If it doesn't work, you don't use enough of it:
Matlab Code time!
clear all;close all;clc;
X = [1:31]'; % Definition of the arrays with all possibilities.
Y = [1:12]';
Z = [1:100]';
U = [2:10]';
V = [2:10]';
C = [3,4];
% Handle C
S = 4002331 - C; % Result is an array of both options for both choices of C
% Handle V
S = repmat(S,[length(V),1]);
V = repmat(V,[1,size(S,2)]);
S = S./V;
S = S(rem(S,1)==0)';
This code replicates the current solutions state for the length of the currently tested variable (in this case V), and does the same for V to have S and V both arrays of equal size. It divides both arrays element-wise. Only divisions which are integer are valid solutions. So we pick out those and use it as our new solutions state. We simply repeat it for all variables and end up with an array of possible solutions for W.
% Handle U
S = repmat(S,[length(U),1]);
U = repmat(U,[1,size(S,2)]);
S = S./U;
S = S(rem(S,1)==0)';
% Handle X
S = repmat(S,[length(X),1]);
X = repmat(X,[1,size(S,2)]);
S = S./X;
S = S(rem(S,1)==0)';
% Handle Y
S = repmat(S,[length(Y),1]);
Y = repmat(Y,[1,size(S,2)]);
S = S./Y;
S = S(rem(S,1)==0)';
% Handle Z
S = repmat(S,[length(Z),1]);
Z = repmat(Z,[1,size(S,2)]);
S = S./Z;
S = S(rem(S,1)==0)';
S = unique(S)
And it turns out that
If the domain of X is limited to 1:28, the resulting solution state S is exactly the same. So we can safely ignore all the hassle associated with dates like the 31st of February, since every month will always have at least 28 days.