"A box contains 100 bulbs 20 of which are   defective. 10 bulbs are selected for inspection.
Channel: Doubtnut
Date: 12/07/2020

"A box contains 100 bulbs 20 of which are
 
  defective. 10 bulbs are selected for inspection. Find the probability that:
 
  i. all 10 are defective ii. all 10 are good ii. at least one is defective iv.
 
  none3 is defective."