5. There are nine coins. One of them is a counterfeit with more weight. The other eight coins have equal weights. How will you find the counterfeit coin using a balance s Sh cale. ow the full decision tree with explanations. How many weightings are needed to find the counterfeit coin. Your solution must be as efficient as possible. 6. There are four coins. One of them is a counterfeit that could be heavier or lighter. The other three coins have equal weights. How will you find the counterfeit coin using a balance scale. Show the full decision tree with explanations. How many weightings are needed to find the counterfeit coin. Your solution must be as efficient as possible