Question:
It is known that a box of 100 electric bulbs contains 8 defective bulbs. One bulb is taken out at random from the box. What is the probability that the bulb drawn is
(i) defective?
(ii) non-defective?
Solution:
Total number of bulbs in the box $=100$
(i) Number of defective bulbs $=8$
$\therefore \mathrm{P}_{(\text {defective bulb })}=\frac{8}{100}=\frac{2}{25}$
(ii) Number of functioning bulbs $=100-8=92$
$\therefore \mathrm{P}_{(\text {non-defective } \text { bulb })}=\frac{92}{100}=\frac{23}{25}$