Question

In a survey of students at a local high school, 30% of the students said they liked tater tots and 15% of the students said they like French fries. If every one of the students who said they like French fries also said they like tater tots, what proportion of the students responding to the survey said they liked at least one of the two side dishes?
3/20
3/10
9/20
11/20
7/10