Question

A mover packs books, CDs, and DVDs into a moving box. If the box contains 6.5 kg of books, 1.5 kg of CDs, and 2.0 kg of DVDs, what is the percent by mass of each object in the box?

Answer 1

Answer:

$\text{Mass percentage}=\frac{\text{Mass of the substance}}{\text{Total mass}}\times 100$

Given: Mass of books = 6.5 kg

Mass of CD's = 1.5 kg

Mass of DVD's = 2.0 kg

Total mass = 6.5 kg + 1.5 kg + 2.0 kg = 10 kg

$\text {Mass percentage of books}=\frac{6.5kg}{10kg}\times {100}=65\%$

$\text {Mass percentage of CD's}=\frac{1.5kg}{10kg}\times {100}=15\%$

$\text {Mass percentage of DVD's}=\frac{2.0kg}{10}\times {100}=20\%$

Answer 2

First, we calculate the total mass.

M = 6.5 kg + 1.5 kg + 2.0 kg =  10 kg

Percent by mass is calculated by getting the ration of the mass of an object and the total mass multiplied by 100 to get the percent.

%M1 = 6.5 / 10 x 100 = 65%
%M2 = 1.5/10 x 100 = 15%
%M3 = 2.0/10 x 100 = 20%