Question

ये वाला भी कोई कर दो.....
वन्देमातरम्​

Answer 1

$\huge\underline{\overline{\mid{\bold{\pink{ANSWER-}}\mid}}}$

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

P (Nuri buys a pen)

=> 124 / 144

=> 31 / 36

(ii) P (Nuri will not buy a pen)

1 - 31 / 36

=> 5 / 36

Answer 2

$\displaystyle\huge\red{\underline{\underline{Solution}}}$

The lot consists of 144 ball pens of which 20 are defective

So good pens = 144 - 20 = 124

Now Nuri will buy a pen if it is good

Now the total number of possible outcomes = 144

1.

Let A be the event that NURI WILL BUY THE PEN

So the total number of possible outcomes for the event A is 124

So the required probability

$P(A) = \displaystyle \: \frac{124}{144} = \frac{31}{36}$

2.

Now the probability that NURI WILL NOT BUY THE PEN

$P(A^{c} ) =1 - P(A) \displaystyle \: = 1 - \frac{124}{144} =1 - \frac{31}{36} = \frac{5}{36}$