Leela stops to get some food at FishyJoes and she sees that

Leela stops to get some food at FishyJoe’s and she sees that 40% of the salads have cheese topping on them, 20% haveranch on them, and 40% are plain. Of the salads with cheese topping, 45% have’froot’ on them; of the salads with ranch, 15% have ‘froot’on them; and of the plain salads, only 10% have froot on them. Leela tells theclerk to choose a salad for her at random. Given that the salad does not have ‘froot’,what is the probability that it is a plain salad?