 Hello and welcome to the session. Let us discuss the following question. Question says, Gobi buys a fish from a shop for his aquarium. The shopkeeper takes out one fish at random from a tank containing 5 male fish and 8 female fish. What is the probability that the fish taken out is a male fish? This is the given figure 15.4. First of all let us understand that probability of occurrence of an event E denoted by P.E. Is defined as number of outcomes favorable to E upon total number of possible outcomes. This is the key idea to solve the given question. Let us now start with the solution. Now we are given that there are 5 male fish and 8 female fish. So total number of fish in the tank is equal to 5 plus 8 that is 13. Now one fish can be taken out in 13 ways. So total number of possible outcomes is equal to 13. We also know that there are total 5 male fishes. So here we can write number of male fishes is equal to 5. Now one male fish can be chosen in 5 ways or we can say one male fish can be taken out in 5 ways. So number of outcomes favorable to male fish is equal to 5. Now we have to find the probability of taking out a male fish. We know it is equal to number of outcomes favorable to male fish upon total number of possible outcomes. From key idea we know probability of an event E is equal to number of outcomes favorable to E upon total number of possible outcomes. So here event is taking out a male fish. So probability of taking out a male fish is equal to number of outcomes favorable to male fish upon total number of possible outcomes. Now we know number of outcomes favorable to male fish is equal to 5 and total number of possible outcomes is equal to 13. So we get probability of taking out a male fish is equal to 5 upon 13. So the required answer is probability that the fish taken out is a male fish is equal to 5 upon 13. This is our required answer. This completes the session. Hope you understood the solution. Take care and have a nice day.