Question

a set of building blocks includes blocks of various shapes and colors. if 10% of the blocks are cubes, and 40% of the cube blocks are red, then what percentage of the blocks are red cubes

Answer 1

Assuming the colours are uniformly distributed over the shapes, we can use the multiplication rule to get
P(red cubes)=P(red)*P(cubes)=0.4*0.1=0.04