Question

12 defective pens are accidentally mixed with 132 good pens it is not possible to just look at prn and tell whether of not it is defective one pen tsken out at random from this lot determine rhe probanility that pen taken out is good one​

Answer 1

no of good pens =132

no of defective pens =12

total pens =132+12=144

randomly picking one pen from total pen=1/144

good pens=1/132

Answer 2

n(S)=144

n(A)=132

p(A)=n(A)/n(S)=132/144=66/77