The mass of a container with sugar was 5.81 kg. When 3/8 of the sugar was removed, its mass became 3.8 kg. What was the mass of the container when it was empty?

Answer 1

Let's denote the mass of the container when it was empty as "x" kilograms.
If 3/8 of the sugar was removed, this means 5/8 of the sugar remained in the container.
So, the mass of 5/8 of the sugar is 3.8 kg.
To determine the mass of 1/8 of the sugar, we can divide 3.8 kg by 5 since 5/8 = 1/8 + 1/8 + 1/8 + 1/8 + 1/8 = 5/8.
So, 3.8 kg / 5 = 0.76 kg is the mass of 1/8 of the sugar.
Since 1/8 of the sugar equates to 0.76 kg, the mass of all the sugar is 0.76 kg x 8 = 6.08 kg.
Therefore, the mass of the container when it was empty is 6.08 kg - 5.81 kg = <<6.08-5.81=0.27>>0.27 kg. Answer: \boxed{0.27}.