In a class of 200 students, forty percent are girls. Twenty-five percent ... ...

In a class of 200 students, forty percent are girls. Twenty-five percent of the boys and 10 percent of the girls signed up for a tour to Washington DC. What percent of the class signed up for the tour?
(A) 19%
(B) ...
(C) ...
(D) ...
(E) ...

*This question is included in Nova Math - Problem Set T: Percents