Direction: Read the following information carefully and answer the following questions.
A class has total 500 students. All the students are involved in exactly one of three different activities, i.e. Dancing, Singing and Photography. Number of students in dancing is 20% of total students in the class and ratio of boys to girls in dancing is 3 : 7. Number of students in photography is 60% of the number of students in singing. Number of girls in Singing is 50 less than number of boys in Singing. Number of girls in photography is 87.5% of number of boys in Photography.
Find the difference between number of boys involved in Photography and Number of girls involved in Dancing.

Options

A. 10
B. 5
C. 15
D. 20