 Hi and how are you all today? The question is given five flags of different colors how many different signals can be generated if each signal requires the use of two flags one below the other. Now here also we will be making use of the multiplication principle. The question says that we need to have two flags one below the other. So we need to fill signals for two vacant places like this. One is now what we have done over here is we have drawn two vacant places to denote the signals and the five the flags which we need to prepare is by the five different colors which are available to us. So we'll start by the first place. Now it can be filled up by any one of the five flags so there are five different ways of filling up the first signal whereas the second place can be filled up by four ways and not five because the flags are of different colors we cannot repeat the colors. The number of ways in which vacant places can be filled in by the multiplication principle is five multiplied by four that is 20. So the number of different signals which can be generated if each signal requires use of two flags one below the other then the required answer is exactly it is 20. This completes the session take care.