$A$ lot consists of $144$ ball pens of which $20$ are defective and the others are good. Nuri will buy a pen if it is good,but will not buy if it is defective. The shopkeeper draws one pen at random and gives it to her. What is the probability that
$(i)$ She will buy it?
$(ii)$ She will not buy it?
$(i)$ She will buy it?
$(ii)$ She will not buy it?
(A) Total number of pens $= 144$
Total number of defective pens $= 20$
Total number of good pens $= 144 - 20 = 124$
$(i)$ Probability of getting a good pen (Nuri buys the pen) $= \frac{124}{144} = \frac{31}{36}$
$(ii)$ Probability of getting a defective pen (Nuri will not buy the pen) $= \frac{20}{144} = \frac{5}{36}$ or $1 - \frac{31}{36} = \frac{5}{36}$
Total number of defective pens $= 20$
Total number of good pens $= 144 - 20 = 124$
$(i)$ Probability of getting a good pen (Nuri buys the pen) $= \frac{124}{144} = \frac{31}{36}$
$(ii)$ Probability of getting a defective pen (Nuri will not buy the pen) $= \frac{20}{144} = \frac{5}{36}$ or $1 - \frac{31}{36} = \frac{5}{36}$
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Similar Questions
$A$ child has a die whose six faces show the letters as given below:
$A$,$B$,$C$,$D$,$E$,$A$
The die is thrown once. What is the probability of getting:
$(i)$ $A$?
(ii) $D$?
$A$,$B$,$C$,$D$,$E$,$A$
The die is thrown once. What is the probability of getting:
$(i)$ $A$?
(ii) $D$?
Medium
View Solution$A$ die is numbered in such a way that its faces show the numbers $1, 2, 2, 3, 3, 6$. It is thrown two times and the total score in two throws is noted. Complete the following table which gives a few values of the total score on the two throws:
+ $1$ $2$ $2$ $3$ $3$ $6$ $1$ $2$ $3$ $3$ $4$ $4$ $7$ $2$ $3$ $4$ $4$ $5$ $5$ $8$ $2$ $3$ $4$ $4$ $5$ $5$ $8$ $3$ $4$ $5$ $5$ $6$ $6$ $9$ $3$ $4$ $5$ $5$ $6$ $6$ $9$ $6$ $7$ $8$ $8$ $9$ $9$ $12$
What is the probability that the total score is
$(i)$ even?
$(ii)$ $6?$
$(iii)$ at least $6?$
| + | $1$ | $2$ | $2$ | $3$ | $3$ | $6$ |
|---|---|---|---|---|---|---|
| $1$ | $2$ | $3$ | $3$ | $4$ | $4$ | $7$ |
| $2$ | $3$ | $4$ | $4$ | $5$ | $5$ | $8$ |
| $2$ | $3$ | $4$ | $4$ | $5$ | $5$ | $8$ |
| $3$ | $4$ | $5$ | $5$ | $6$ | $6$ | $9$ |
| $3$ | $4$ | $5$ | $5$ | $6$ | $6$ | $9$ |
| $6$ | $7$ | $8$ | $8$ | $9$ | $9$ | $12$ |
What is the probability that the total score is
$(i)$ even?
$(ii)$ $6?$
$(iii)$ at least $6?$
Difficult
View SolutionSomeone is asked to take a number from $1$ to $100$. The probability that it is a prime number is
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View Solution$A$ card is drawn at random from a well-shuffled pack of $52$ cards. Find the probability that the card drawn is a face card.
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View SolutionThere are boards numbered $1$ to $50$ in a box. One board is selected at random. Find the probability that the number on the board is a prime number.
Easy
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