The alloy consists of 5 parts of copper 3 parts of zinc (by mass) what is the mass of copper

The alloy consists of 5 parts of copper 3 parts of zinc (by mass) what is the mass of copper and what is the mass of zinc in 2 point four-fifths of a kg of alloy?

To solve this problem, you need to write an equation. Let one part be -x kilogram, then copper – 5x kg, and zinc – 3x kilogram. Let’s calculate the mass of zinc and copper in 2 whole 4/5 kilograms. Let’s make an equation.
5x + 3x = 2 4/5;
8x = 14/5;
x = 14/5: 8 = 14/5 * 8 = 14/40 = 7/20 kg.
They calculated that one part is equal to 7/20 kilograms, then copper 5 * 7/20 = 7/4 = 1 whole 3/4 kg., And zinc 3 * 7/20 = 21/20 = 1 whole 1/20 kilogram.
Answer: 1 whole 3/4 kg, 1 whole 1/20 kg.