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 400 circuit boards where 64 fail inspection?	Options:
A) 106  B) 192  C) 200  D) 256  E) 264
Total of 400 boards. All that fail verification are indeed faulty. So the 64 are indeed faulty. 1/8 those that pass are also faulty.   From the 400 we know 64 fail. So 336 must pass. Of these 1/8 are faulty. 336 divided by 8 gives you 42.   What one must do now is to add to the 42 which were not detected the actually detected faulty ones, namely the 64.   Total faulty: 106.   106nswer: 106
<result>A</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 400 circuit boards where 64 fail inspection?