1.there are 100 students in a college of which 36 are boys studying statistics and 13 girls not studying statistics. if there are 55 girls in all, then the probability that a boy is picked up iat random is noyt studying statistics, is
a.3/5 b.2/5
c.1/5 d.none of these
sol:there are 55 gals then remaining 45 are boys out of which 36 are studying stat then only 9 not studying
therefore 9/45 =1/5

2.An article manufactured by a company consists of two parts X and Y. In the process of manufacture of the part X, 9 out of 104 parts may be defective. similarly, 5 out of 100 are likely to be defective in the manufacture of the part Y. the probability that the assembled product will not be defective, is
sol:9 out of 104=95(not def)
5 out of 100(not def)
therefore req prob=(95/104)(95/100)=361/416