In Mr. Senter's classroom, 3/5 of the students play chess. Of the students who play chess, 5/6 also play sudoku. If there are 30 students in his class, how many play chess and sudoku?. PLZ ANSWER FAST WILL MARK BRAINLIEST

Afamily has two cars. the first car has a fuel efficiency of 25 miles per gallon of gas and the second has a fuel efficiency of 15 miles per gallon of gas. during one particular week, the two cars went a combined total of 1025 miles, for a total gas consumption of 55 gallons. how many gallons were consumed by each of the two cars that week?