Question

A packet containing 400 screw, 140 screw are defective. A screw is picked up randomly from the packet. Then find the probability that the screw picked up is non-defective

Answer 1

first the no of non-defective screws are 400 - 140 = 260

probability = 260/400 = 13/20

probability(in %) = 13/20 X 100 = 65%

hope it helps...

Answer 2

Total screw 400

Deffective screw 140

Good screws=400-140=260

Probablity =no. of favourable outcomes

Total no. of outcomes

=260

400

=13

. 20

So the non defective screws is 13

20