In the alloy, the mass of copper refers to the mass of tin as 2: 5, and the mass of tin to the mass of antimony as 3: 1.

In the alloy, the mass of copper refers to the mass of tin as 2: 5, and the mass of tin to the mass of antimony as 3: 1. In the alloy of tin, 135 g more than copper. Find the mass of the alloy.

Let us denote the mass of copper by the letter “m”, the mass of tin by the letter “o”, and the mass of antimony by the letter “c”.

By the condition of the problem, we get:

m: o = 2: 5,

o = 5 * m / 2.

We also know that o – m = 135.

Let’s substitute the obtained value about in this expression:

5 * m / 2 – m = 135,

5 * m – 2 * m = 270,

m = 270: 3,

m = 90 (g) is the mass of copper.

So the mass of tin is equal to:

o = 5 * 90: 2 = 225 (g).

Since o: c = 3: 1, the mass of antimony is equal to:

c = 225: 3 = 75 (d).

Thus, the mass of the alloy is equal to:

90 + 225 + 75 = 390 (g).