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# A letter lock consists of three rings each marked with $5$ different letters. Number of maximum attempts to open the lock is:A. $124$ B. $125$ C. $120$ D. $75$  Verified
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Hint: Find the number of ways of choosing the letter for each of the three rings and then multiply the number of ways to open all the locks of the letter lock. We can also use concepts of permutations and combinations to solve such problems.

A letter lock consists of three rings each marked with $5$ different letters.
As per given that the letter lock consists of three rings each marked with $5$ different letters.
So, the number of ways for opening the first ring is equal to $5$ as it is marked with $5$ different letters.
In a similar manner, the number of ways for opening the second ring is equal to $5$ as it is marked with $5$ different letters.
In a similar manner, the number of ways for opening the third ring is equal to $5$ as it is marked with $5$ different letters.
So, the number of ways for opening the letter lock is equal to $5 \times 5 \times 5 = 125$ .
So, the number of maximum attempts to open the lock is equal to $125$