Answer:
2/3
Step-by-step explanation:
5 black
3 green (not black)
3 blue (not black)
4 yellow (not black)
there are 5 black and 10 not black out of a total of 15 marbles.
there are 10/15 that are not black. Reduced 2/3.
I think it would be layer 4
Answer:

Step-by-step explanation:
In all 30-60-90 triangles, the side lengths are in ratio
, where
is the side opposite to the 30 degree angle and
is the hypotenuse, or longest side, of the triangle.
Since there are 180 degrees in a triangle, the angle on top must be 30 degrees. Therefore, its opposite side is 6 and
in the ratio
.
Thus, we have:

Answer:
12%
Step-by-step explanation: