Question

A box contains 120 screws. During quality check, it is found that five screws are
defective. If one screw is chosen at random from the box, what is the probability that it
is not defective?

Answer ASAP please, I'll mark brainliest

Answer 1

Answer:

Here at least 2 items are defective out of 4. So the no. of defective items can be 2 or defective can be 3.

Total no. of defective ites =3

If 2 items are defective =

3

C

2

×

7

C

2

=63

If 3 items are defective =

3

C

3

×

7

C

1

=7

Probability that atleast 2 out of 4 items are defective =

10

C

4

63+7

=

210

70

=

3

1

Step-by-step explanation:

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Answer 2

Answer:

total outcomes=120

favourable outcomes=120-5=115

p( getting a screw which is not defective)= total outcomes /favourable outcomes=115/120=23/24

so probability that the screw is not defective is 23 /24