From a box containing a dozen bulbs, of which exactly one half are good, and four bulbs are chosen at random to fit into the four bulb holders in a room. The probability that the room gets lighted is

• Probability that room is lighted means atleast one of the four bulbs picked is good...
  so required prob=1-(prob that all bulbs picked are defective)
  1-(6/12*5/11*4/10*3/9)=32/33...
  is this correct?????
• 12 years agoHelpfull: Yes(10) No(5)
• room get light means at least 1 bulb should be good
  4 conditions are 1good 3 defective or 2 good or 3 good or 4 good
  probilty of one good rest defective= 6c1*6c1*6c1*6c1/12C4
  same as find for 4 case then add
• 12 years agoHelpfull: Yes(0) No(1)