Of all the flashlights in a large shipment, 15 % have a defective bulb, 15 % have a defective battery, and 5 % have both defects. If you purchase one of the flashights in this shipment, find the probability that it has the following:
a. a defective bulb or a defective battery
b. a good bulb or a good battery
c. a good bulb and a good battery
2007-12-09 17:24:27 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
a)
P(A) + P(B) - P(A & B) =
P(deffective bulb) + P(deffective battery) - p(deffective bulb & deffective battery)
15% +15% -5% = 25%
2007-12-09 17:29:38 · answer #1 · answered by Christopher 2 · 0⤊ 0⤋
a) 15 - 5% + 15 - 5% = 20% chance
b) 95% as only 5% have both defects
c) 100-30-5 = 75 % are good for both
changed my answer - ooops
2007-12-09 17:30:25 · answer #2 · answered by tom4bucs 7 · 0⤊ 0⤋