Draw a picture, with A as the ordinate and B as the abscissa, and get a rectangular area of 4 on the map.

A and b that meet the conditions meet the inequality group: a >；; b，a & lt2b

Draw an area that meets the conditions, and the ratio of the two areas is the probability.

This is the content of compulsory three. If you are not sure, you can check it again. There are examples in the textbook.