! Solution: z* = 30 2/3, x* = (11, 8, 11)/30
! costs given elsewhere
min 40 x1 + 60 x2
st
balancin) x1 + x2 + x3 = 1
nutrA) 100 x1 + 200 x2 > 90
nutrB)  80 x1 + 150 x2 > 50
nutrC)  40 x1 +  20 x2 > 20
nutrD)  10 x1 > 2
end