Let\(E_1\) be a person selected be 'o' group

\(E_2\) be a person selected be of non 'o' group

A; He is left handed person

P(\(E_1/A\))=P(\(he\; is\; 'o' \;group/he \;is\; left \;handed\))

P(E\(_1\)/A)\(\Large\frac{{p(E_1)}{P(A/E_1)}}{{P(E_1)}{P(A/E_1)}+{P(E_2)}{P(A/E_2)}}\)

P\(E_1\)=P(He is 'o' group)=\(\large\frac{30}{100}\)=\(\large\frac{3}{10}\)

P\(E_2\)=P(He isnot 'o' group)=\(\large\frac{70}{100}\)=\(\large\frac{7}{10}\)

P(\(A/E_1\))=P(He is left handed /he is'O' groyp)

=\(\large\frac{6}{100}\)

P(\(A/E_2\))=P(He is left handed /he is not 'O' groyp)

=\(\large\frac{10}{100}\)

P(\(E_1/A\))=\(\Large\frac{\frac{3}{10}\times\frac{6}{100}}{\frac{3}{10}\times\frac{6}{100}+\frac{7}{10}\times\frac{10}{100}}=\frac{3\times6}{3\times6+7\times10}\)

=\(\large\frac{18}{88}\)

=\(\large\frac{9}{44}\)