Answer:
C. 10 grams
Step-by-step explanation:
Taking into account the figure, we get that:
The mass of 2 squares, 6 triangles, and 2 circles is equal to the mass of 2 circles, 4 squares, and 2 triangles.
So, if we call x the mass of the square, we can formulate the following equation:
2x + 6(5) + 2(2) = 2(2) + 4x + 2(5)
2x + 30 + 4 = 4 + 4x + 10
Because the mass of the triangles is 5 grams and the mass of the circles is 2 grams.
Then, solving for x, we get:
2x + 34 = 14 + 4x
2x + 34 - 2x = 14 + 4x - 2x
34 = 14 + 2x
34 - 14 = 14 + 2x - 14
20 = 2x
20/2 = 2x/2
10 = x
Therefore, the mass of a square is 10 grams.