Question

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 stirs 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 a boy ?

Answer 1

Total number of students = 40.

Number of boys = 15.

Number of girls = 25.

Let E₂ be the event of getting a boy's name on the card.

∴ P(selecting the name of a boy) = P(E₂) = `("Number of outcomes favourable to"  E_2)/"Number of all possible outcomes"`

`= 15/40 = 3/8`

Thus, the probability that the name written on the card is the name of a boy is `3/8`.