Answer:72 bulbs
Step-by-step explanation:
Given
Ratio of defective light bulbs produced to total light bulbs produced is about
3:500
that is if 503 bulbs are manufactured then 3 are defective
let x be the non-defective bulbs in 12000 bulbs
defective bulbs=[tex]x\times \frac{3}{500}[/tex]
therefore
12000=Non-defective +defective
[tex]12000=x+x\times \frac{3}{500}[/tex]
[tex]12000=\frac{503}{500}\times x[/tex]
[tex]x=11,928.42\approx 11,928[/tex]
Therefore Defective bulbs =12000-11928=72 bulbs