Gopi 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 (see Fig. 15.4). What is the probability that the fish taken out is a male fish?
As per the question,
Total number of fishes in a tank
= Number of male fishes + Number of female fishes
= 5 + 8 = 13
Probability of a male fish = 
= 
18