There is a bag with only red marbles and blue marbles. The probability of randomly choosing a red marble is
7/10th

There are 42 red marbles in the bag and each is equally likely to be chosen.
Work out how many marbles in total there must be.

Solve the problem by using a venn diagram a group of students were surveyed about their taste in music.they were asked how they like three types of music: rock, country western and jazz.the results are summarized below: no one dislikes all three types of music.six like all three types of music.eleven don’t like country western.sixteen like jazz.three like country western and jazz, but not rock.six don’t like rock.eight like rock and country western.seven don’t like jazz.how many students were surveyed?