In a circuit board factory, all circuit boards that pass a verification process are certified. Every board that fails the verification process is indeed faulty, but 1/8 of those that pass are also faulty.
Approximately how many faulty circuit boards exist in a group of 800 circuit boards where 64 fail inspection?  Choices: A) 72 B) 192 C) 156 D) 256 E) 264
Total of 800 boards. All that fail verification are indeed faulty. So the 64 are indeed faulty. 1/8 those that pass are also faulty.   From the 800 we know 64 fail. So 736 must pass. Of these 1/8 are faulty. 736 divided by 8 gives you 92.   What one must do now is to add to the 92 which were not detected the actually detected faulty ones, namely the 64.   Total faulty: 156.   Answer: 156
<result>C</result>
In a circuit board factory, all circuit boards that pass a verification process are certified. Every board that fails the verification process is indeed faulty, but 1/8 of those that pass are also faulty.
Approximately how many faulty circuit boards exist in a group of 800 circuit boards where 64 fail inspection?