statistics
posted by hhhh .
among the exames in the examination 30%, 35% & 45% failed in statistics, in maths, & in atleast one of the subjects respectively. one student is selected at random. find the probability that: (a)he has failed in maths, (b)he passed in statistiics if it is known that he has failed in maths

i think that the question is not complete but it could be p(fail in math)= 35%
we don't know the sample size,or pop. size, even not the the x.