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 3,200 circuit boards where 64 fail inspection? Choose the correct choice from the following options
A) 72
B) 192
C) 456
D) 256
E) 264
Total of 3,200 boards. All that fail verification are indeed faulty. So the 64 are indeed faulty. 1/8 those that pass are also faulty.   From the 3,200 we know 64 fail. So 3,136 must pass. Of these 1/8 are faulty. 3,136 divided by 8 gives you 392.   What one must do now is to add to the 392 which were not detected the actually detected faulty ones, namely the 64.   Total faulty: 456.   Answer: 456
<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 3,200 circuit boards where 64 fail inspection?