Probability
posted by Johnson on .
Two group of male students cost their past on a particular proposal.the result are as follows: Group infavour against A 128 32 B 96 48 <a> if a student in favour of proposal is selected for a post. What is the probability that he is from group A ? if a student is chosen at random, what is the probability that he is against proposal.

Nuts to this, it makes no sense.
What does "cost their past" mean?
If you mean
group A in favor: 128
group A opposed: 32
group B in favor: 96
group B opposed: 48
Now if all those infavor (128+96), if one is selected, Pr(A)=128/(128+96)
If a student is chosen at random,
Pr(against)=totalagainst/total students
= (32+48)/(128+32+96+48) 
I am also confused by what "in favour against" means.