Question 1 of 50

The mass of a box completely filled with sand is 9kg. If $\frac{1}{3}$ of the sand is poured out, the mass of the box and the remaining sand is 6.1kg. What is the mass of the empty box?

A
0.2kg
B
0.3kg
C
0.4kg
D
0.5kg
E
None of the above