Question

A flashlight has 10 batteries out of which 4 are dead. If 3 batteries are selected without replacement and tested, then the probability that all 3 are dead is

• A. $\frac{1}{30}$
• B. $\frac{2}{8}$
• C. $\frac{1}{15}$
• D. $\frac{1}{10}$

Answer 1

Answer: (A)

$\frac{1}{30}$

Answer 2

The required probability = $\frac{4}{10} \times \frac{3}{9} \times \frac{2}{8} = \frac{1}{30}$