The total mass of the three pieces of granite is 156 kg. a piece of gray granite is 18 kg heavier

The total mass of the three pieces of granite is 156 kg. a piece of gray granite is 18 kg heavier than a piece of red granite, and a piece of red granite is 15 kg lighter than a piece of white granite. find a mass of gray, white and red granite

Let’s denote the mass of a red piece of granite – x;
Mass of the gray piece: x + 18;
White piece mass: x + 15;
Then:
1) 156 = x + x + 18 + x + 15;
3x = 156 – 33 = 123 kg.
2) The mass of the red piece of the piece:
x = 123/3 = 41 kg;
3) Weight of the gray piece:
41 + 18 = 59 kg;
4) The mass of the white piece:
41 + 15 = 56 kg;
Answer: 41 kg – red, 59 kg – gray, 56 kg – white.