Answer: 985 g
Step-by-step explanation:
Total mass = 8 × 500g = 4000g
Let the three new packs be X, Y, and Z, for first, second, and third pack respectively.
4000g = X + Y + Z
let's put X and Z in terms of Y, since we're trying to solve for the second pack.
X = 2Y, and Z = Y + 60
Therefore,
4000 = X + Y + Z
4000 = 2Y + Y +Y + 60
4000 = 4Y +60
4000 - 60 = 4Y
3940 = 4Y
3940 ÷ 4 = Y
985g = Y = mass of the second pack