I got stuck in the first question of the second section of the math question and had to rush the rest of the of the test, however this is in line to the rest of the SAT test I took

Answer to yesterday's was -7. A community program has 300 members, some teens and some adults. Of the teen members, 70% volunteered at least once this month. Of the adult members, 40% volunteered at least once this month. If 60% of all members volunteered at least once this month, what percent of the members are teens? A) 60% B) 50% C) 70% D) 66.667%