edited by
1,053 views
2 votes
2 votes

A box contain 10 screws out of which 3 are defective.If two screws are drawn at random WITH REPLACEMENT.What is the probability that no screw is defective?

Answer given as 7c2/10C2

my question is ,as its given With Replacement. So why not it is (7/10)*(7/10)

edited by

2 Answers

Best answer
6 votes
6 votes

......................

selected by
3 votes
3 votes

See here the key thing is :

a) The population which is a box of  10 screws and hence finite .

b) Screws are drawn with replacement.

So the assumption of binomial distribution will hold..

So P ( no defective ) = 2C0 (7/10)2

                               = 0.49

Hence 0.49 is correct answer.. 

Related questions

0 votes
0 votes
0 answers
1
Swarnava Bose asked Jun 8, 2023
211 views
What is the total number of integer partitions ( unordered Summation) of the natural number 8 ?I am getting 22. Is it correct ?
0 votes
0 votes
2 answers
2
Ayush Upadhyaya asked Aug 29, 2018
459 views
Number of ways to distribute 5 distinct toys to 3 children A,B,C such that each one of them gets atleast one toy.My answer come to be 75.Is it correct? Also, when toys ar...