On Sunday, a cafe sold 49 cartons of milk. The ratio of cartons of chocolate milk sold to the total number of cartons of milk sold was 2:7. How many cartons of chocolate milk did the cafe sell on Sunday?​

The students in a class were asked how many siblings they have. the data obtained is represented in the dot plot. the number of students who have no siblings is . the number of students who have three or more siblings is .