The Total solution for NCERT class 6-12
Let E1 bethe event that item is produced by A, E2 be the event that itemis produced by B and X be the event that produced product is found to bedefective.
Then P (E1)= 60% = 60/100 = 3/5
P (E1) =40% = 40/100 = 2/5
Also P (X|E1)= P (item is defective given that it is produced by machine A) = 2% = 2/100 =1/50
And P (X|E2)= P (item is defective given that it is produced by machine B) = 1% = 1/100
Now the probabilitythat item is produced by B, being given that item is defective, is P (E2|A).
By using Bayes’theorem, we have