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Aptitude · Q36

Probability

Competitive Exams · Aptitude · question 36

Q36

A box contains 20 electric bulbs, out of which 4 are defective. Two balls are chosen at random from this box. The probability that at least one of them is defective, is -

A.
B.
Answer
C.
D.
E.
None of these

Answer: Option B

Solution

Answer: Option B
Solution:
P (none is defective)
= n (E) =      
P (at least 1 is defective)
=