There are 90 students who have lunch during period 5. Today, two-thirds of the students sat in the cafeteria, while the remainder sat at the covered picnic tables outside. But some yellow-jackets were attracted to their food, and so one-third of the students outside jumped up and ran inside to the cafeteria, while 3 of the students in the cafeteria went outside to see what all the fuss was about. How many students are now in the cafeteria?
What is the solution?
Originally, there were 90*2/3=60 in the cafeteria.
Originally, there were 90-60=30 outside the cafeteria.
Then 30*1/3=10 ran inside
The number of students inside the cafeteria grew by 10-3=7.
There are now 60+7=67 students in the cafeteria.