A silver ball with a volume of 2 cm ^ 3 and a gold ball with a volume of 1 cm ^ 3 together weigh 40.3 g.

A silver ball with a volume of 2 cm ^ 3 and a gold ball with a volume of 1 cm ^ 3 together weigh 40.3 g. Find the density of silver and the density of gold if it is known that the silver ball is 1.7 g heavier than the gold one

The density of silver is denoted by X, and the density of gold by Y;
The weight of the silver ball is 2 * X, and the weight of the gold ball is Y;
Let’s compose the equations:
2 * X + Y = 40.3,
2 * X – Y = 1.7;
Let’s solve the system. Let’s take the sum of the equations:
4 * X = 42;
The density of silver is:
X = 42/4 = 10.5g / cm ^ 3;
Find the density of gold from the first equation:
Y = 40.3 – 2 * X = 40.3 – 21 = 19.3g / cm ^ 3.