ω₁ = 21% ÷ 100% = 0.21.
ω₂ = 42% ÷ 100% = 0.42.
ω₃ = 38% ÷ 100% = 0.38.
m₁ = ?.
m₂ = ?.
m₃ = m₁ + m₂.
m₃ = 41 pounds.
m₁ = 41 lb - m₂.
ω₁ · m₁ + ω₂ ·m₂ = ω₃ · m₃.
0.21 · (41 lb - m₂) + 0.42 · m₂ = 0.38 · 41 lb.
8.61 lb - 0.21m₂ + 0.42m₂ = 15.58 lb.
0.21m₂ = 6.97 lb.
m₂ = 6.97 lb ÷ 0.21.
m₂ = 33.2 lb.
m₁ = 41 lb - 33.2 lb.
m₁ = 7.8 lb.