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प्रश्न
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 ?
उत्तर
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`.
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