Direction: Read the following information carefully and answer the following questions.

A class has a total of 500 students. All the students are involved in exactly one of three different activities, i.e. Dancing, Singing, and Photography. The number of students in dancing is 20% of total students in the class and the ratio of boys to girls in dancing is 3: 7. The number of students in photography is 60% of the number of students in singing. The number of girls in Singing is 50 less than the number of boys in Singing. The number of girls in photography is 87.5% of the number of boys in Photography.