Shall I get a better algorithm about mixture from some components?

Material 'A', 'B', 'C', 'D', 'E', 'F'..........

A is formed by x1--20%,x2--10%,x3--20%,x4--30%,others--20%

B is formed by x1--40%,x2--20%,x3--10%,x4--0%,others--30%

C is formed by x1--0%,x2--50%,x3--0%,x4--0%,others--50%

D is formed by x1--30%,x2--0%,x3--30%,x4--30%,others--10%

E is formed by x1--10%,x2--30%,x3--0%,x4--20%,others--40%

F is formed by x1--20%,x2--20%,x3--0%,x4--0%,others--60%

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and A is $30/kg, B $50/kg, C $40/kg, D $80/kg, E $60/kg, F $30/kg...

Now I want to get a mixture 'X' which formed by x1--25% x2--30% at cheapest price.

Shall I get a better algorithm for it?

Thank you!

[John D'Errico]

What "algorithm"?

How can we know if you should use a better algorithm if you don't even say what you did? Your current algorithm is just fine. Or maybe not.

The crystal ball is so cloudy.