8.

(a) Your local Be-Computer store has received 10 containers with100 bePads in each container. Each bePad is marked to identify thecontainer it is from. Other than that, all bePads are identical andweigh exactly one pound, except for those in one container thathave a manufacturing defect. Those defective bePads weigh exactly17 ounces each. You are asked to identify the bad container. Ofcourse, you could weigh one bePad from each container until yourscale measures 17 ounces. But this process may take 10 weighingsand you are asked to instead use only one single weighing. The goodnews is that your scale is an industrial grade (single platform)scale and you can place any number of bePads on its platform. Howthen do you identify the problematic container by finding theweight of just one collection of bePads selected from variouscontainers?

(b) Having heard of your success with single weighings, the nexttown’s Be-Computer store calls you for help. They have received 7containers (with 100 bePads in each) and know that some of thesecontainers may be coming from the lot of defective 17-ounce bePads.However, they don’t know how many containers are bad. It could beany number, including all or none. How can you in a single weighingidentify all the bad containers?