When two metals with the same volume (density P1 and P2) are cast into alloy, what is the alloy density?

When two metals with the same volume (density P1 and P2) are cast into alloy, what is the alloy density?

The weight of the alloy is P1V + P2V
The volume is 2V (because the two metals have the same volume)
So the new density is (P1V + P2V) / 2V = (P1 + P2) / 2

The total metal volume density of the cast ductile iron is 2.5% of the total metal volume density
(density of iron: 7.8 × 10 ^ 3 kg / m ^ 3. Density of lead: 11.3 × 10 ^ 3 kg / m ^ 3)

V Fe + V Pb = 2.5
7.8v Fe / (7.8v Fe + 11.3v Pb) = 30%
The results are as follows: V Fe = 0.96 (DM3); V Pb = 1.54 (DM3);
M iron = 7.488kg m lead = 17.402kg m ball = 24.89kg
Ball density = 24.89 / 2.5 = 9.956 (kggm3) = the third power of 9.956 * 10 (kg / m3)

Given the density of two metals, how to find the density of their alloy
The alloy is made of two metal compounds with equal mass and density P1 and P2 respectively?

The alloy is made of two metal compounds with equal mass and density P1 and P2 respectively?
Let their masses be m, then their volumes are
V1=m/ρ1,V2=m/ρ2
According to the definition of density:
ρ=(m+m)/(m/ρ1+m/ρ2)=2ρ1ρ2/(ρ1+ρ2)