There are 40 students in a class of whom 25 are girls and 15 are boys. The class teacher has to select one student as a class representative. He writes the name of each student on a separate card, the cards being identical. Then, she puts cards in a bag and sites them thoroughly. She then draws one card from the bag. What is the probability that the name written on the card is the name of (i) a girl? (ii) a boy?
Total numbers of elementary events are: 40
(i) Let E be the event of drawing a card with girl`s name written on it
The numbers of favourable outcomes are: 25
∴ P (girl`s name) = P (E)= 25/40 = 5/8
(ii) Let E be the event of drawing a card with boy`s name written on it
The numbers of favourable outcomes are: 15
∴ P (boy`s name) = P (E) = 15/40 = 3/8