Question

A sample of 4 different calculators is randomly selected from a group containing 46 that are defective and 26 that have no defects. What is the probability that all four of the calculators selected are defective? Round to four decimal places.
a. 0.1666
b. 10.9154
c. 0.1586
d. 0.1021

Answer 1

Answer: Option 'c' is correct.

Step-by-step explanation:

Since we have given that

Number of defective calculators = 46

Number of non defective calculators = 26

Total number of calculators is given by

$46+26=72$

According to question,

Number of calculators is randomly selected = 4

So, Probability that all four of the calculators selected are defective is given by

$P(E)=\frac{^{46}C_4}{^{72}C_4}\\\\P(E)=\frac{46\times 45\times 44\times 43}{72\times 71\times 70\times 69}\\\\P(E)=0.1586$

Hence, Option 'c' is correct.

Answer 2

46+26=72
46/72*46/72*46/72*46/72=0.1666101……=0.166