7(x+1)=21 solve for x

What are the relative frequencies to the nearest hundredth of the columns of the two-way table? a b group 1 102 34 group 2 18 14

How to solve a simultaneous equation involved with fractions?

There are three bags: a (contains 2 white and 4 red balls), b (8 white, 4 red) and c (1 white 3 red). you select one ball at random from each bag, observe that exactly two are white, but forget which ball came from which bag. what is the probability that you selected a white ball from bag a?