Please help with parts a-b!

(5 pts.) Searching for fake coins. There are n coins c1,c2,,cn at most two of which are fake. The genuine coins weigh the same and so do the fake coins, but the fake coins are lighter than the genuine ones. Your goal is to use a weighing scale (shown below) to determine all the fake coins in O(logn) weighings. Here's a simple procedure when n=3 : First, compare c1 and c2. There are three possibilities: they weigh the same, c1 is heavier than c2 or c1 is lighter than c2. Next, compare c1 and c3. Again, there are three possibilities. The table below summarizes the conclusion based on the outcomes of the two weighings. Basically, the lighter coin(s) has to be a fake coin(s). We've shown that two weighings suffice to identify fake coins in a group of three coins. a. (1.5 pt.) When n=9, describe a similar procedure that would identify all the fake coins using at most six weighings. b. (3.5 pts.) Create a general procedure for identifying fake coins when n3 using O(logn) weighings. Make sure you justify why the number of weighings is O(logn). NOTES: (i) You are allowed to put more than one coin on each side of the scale. (ii) For clarity, briefly describe your procedure using words and then present the steps like code