Question

It is known that a box of 600 electric bulbs contains 12 defective bulbs. One bulb is taken out at random from this box.What is the probability that it is a non-defective bulb?

• A. $\frac{49}{50}$
• B. $\frac{45}{70}$
• C. $\frac{1}{60}$
• D. $\frac{1}{50}$

Answer 1

The correct option is A $\frac{49}{50}$

One bulb can be chosen in 600 ways.
$\therefore$ Total number of outcomes $=600$
Number of non-defective bulbs $=600-12=588$
$\therefore$ number of outcomes we are interested in $=588$
Hence, p(getting a non-defective bulb) $=\frac{Totalnumberoffavourableoutcomes}{Totalnumberofoutcomes}=\frac{588}{600}=\frac{49}{50}$