Assume the doors to 200 storage bins, ordered from 1-200, are manipulated as follows. Step 1- all doors opened Step 2 - doors for bins in even numbered positions are closed. Step 3 – the door for every third bin is reversed (closed if open and opened if closed) Step 4 – the door for every fourth bin is reversed (closed if open and opened if closed) And so on until 200 steps have been completed. Which doors are open?
Permutations and Combinations
If there are 5 dishes, they can be relished in any order at a time. In permutation, it should be in a particular order. In combination, the order does not matter. Take 3 letters a, b, and c. The possible ways of pairing any two letters are ab, bc, ac, ba, cb and ca. It is in a particular order. So, this can be called the permutation of a, b, and c. But if the order does not matter then ab is the same as ba. Similarly, bc is the same as cb and ac is the same as ca. Here the list has ab, bc, and ac alone. This can be called the combination of a, b, and c.
Counting Theory
The fundamental counting principle is a rule that is used to count the total number of possible outcomes in a given situation.
Trending now
This is a popular solution!
Step by step
Solved in 2 steps
