answere is 28 rows
here there is no logic just thinking
like this way
first step first persion enter to the database
in second step second persion enter to the database
in third step william sees 12 rows in the toys table that means toys table contain
12 rows
in fourt step third persion log on to the same database
in fifth step second persion sees 12 rows in the toys table that time also toys table
contains 12 rows
in sixth step first persion insert 2 rows into the toyps table that time toys table
contain 14 rows
in sevents step second persion insert 14 rows into the toys table that time toys table
contain 28 rows
in eighth step second persion issues the commit that means all rows are commit
so 28 rows are commit in toys table
in ninth step first pesion issue rollback that time also 28 rows avilable in toys table
in 10th step third persion look to toys table that time he sees 28 rows in toys table