Using the given information, the density of metal B is 8.58 g/cm³
<h3>Calculating density </h3>
From the question, we are to determine the density of metal B 
From the given information, 
55 g of metal A is combined with metal B to create an alloy with mass 90 g
∴ Mass of metal B in the alloy = 90 g - 55 g = 35 g
Now, we will determine the volume of metal A in the alloy 
Using the formula, 
Density = Mass / Volume 
∴ Volume = Mass / Density
Volume of metal A in the alloy = 55/12.7 
Volume of metal A in the alloy = 4.33 cm³
Then, we will determine the volume of the alloy 
Volume of the alloy = 90/10.7
Volume of the alloy = 8.41 cm³
∴ Volume of metal B in the alloy = 8.41 cm³- 4.33 cm³
Volume of metal B in the alloy = 4.08 cm³
Now, for the density of metal B 
Density = mass / volume 
Density of metal B = 35 / 4.08 
Density of metal B = 8.58 g/cm³
Hence, the density of metal B is 8.58 g/cm³. 
Learn more on Calculating density here: brainly.com/question/13986137
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