The Hinterland Electric substation team loved doing work at the Company’s Sellmore power plant. It was great seeing how the “other half” lived, plus there were always snacks available in the plant’s community room. The only downside was the station superintendent was hard to please.
Today’s assignment was easy. Frank and Bruce had to install a new disconnect switch in the substation located at the wastewater treatment plant. Due to the corrosive nature of the water vapor in the plant, the switch needed to be installed with Titanium bolts. The guys arrived at the site and alerted the treatment plant operator to start a prearranged half hour outage at the substation. When Frank opened the back of the truck to get the materials for the install, he found the bolts for fastening the switch had rolled onto the floor and instead of the required 15 bolts, there were 16 identical bolts on the floor. Frank knew he had steel bolts for another job and one must have become mixed with the Titanium bolts. And, he knew he and Bruce would never be invited back to the plant if they installed a steel bolt that would quickly rust.
With the clock ticking on the outage, Frank told Bruce what had happened. Bruce said not to worry because there was a two tray balance scale in the lab and they could weigh the bolts to find the intruder. However, they would not have time to finish the install during the outage if they weighed the bolts individually. What is the least number of weight trials, Frank and Bruce could use to single out the steel bolt? Please explain the trials.
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