In a suburban community, 30% of the households use Brand A toothpaste, 27% use Brand B, 25% use Brand C, and 18% use Brand D. In the four groups of households, the proportions of residents who learned about the brand they use through television advertising are as follows: Brand A, 0.10; Brand B, 0.05; Brand C, 0.20; Brand D, 0.15. In a household selected at random from the community, it is found that residents learned about the toothpaste through television advertising. What is the probability that the brand of toothpaste used in the household?