X is equal to 12
This is because 5 was multiplied and 6 making 30. So you have to multiply 2 and 6 making x 12. Hope that makes sense
Exp prob (red) = 24 / 60 = 4 / 10 = 2/5
Theoretical prob (red) = (1/2)
Exp prob (blue) = 14 / 60 = 7 / 30
Theoretical prob (blue) = 1/6
Exp prob ( yellow) = 22/ 60 = 11/30
Theoretical prob ( yellow) = 2/6 = 1/3
Let 
be the volume of 20% solution, 
the volume of the 60% solution. We want a total volume of 400 mL in the final mixture, so
Each mL of either solution will contribute a corresponding concentration, and in the final mixture we want the 400 mL to have a 40% concentration, which means we should also have
Solve the system and we get 
.
defective : working = 1/15 ( x20 ) 20/300
so the answer is 20 light bulbs
