8. Calculate the defective and total number of bulbs

In a box, there are 20 non-defective and some defective bulbs. If the probability that a bulb selected at random from the box found to be defective is $\frac{4}{6}$ then, find the number of defective bulbs and total number of bulbs.

 

i) The number of defective bulbs:

 

 

ii) The total number of bulbs: