Question

It is known that a box of 800 electric bulbs contains 36 defective bulbs. One bulb is taken at random out of the box. What is the probability that the bulb chosen is non-defective?

Answer 1

ANSWER:
Total number of electric bulbs in the box = 800
Number of defective electric bulbs in the box = 36
∴ Number of non-defective electric bulbs in the box = 800 − 36 = 764
P(Bulb chosen is non-defective)
=$\frac{\text{Number of non defective electric bulbs in the box}}{\text{Total number of electric bulbs in the box}}=\frac{764}{800}=\frac{191}{200}$
Thus, the probability that the bulb chosen is non-defective is $\frac{191}{200}$.