Stoney Hollow Middle School is taking a field trip to the zoo. There are 109 fifth graders, 115 sixth graders, and 118 seventh graders. There are 4 teachers and 2 parents from each grade coming along to chaperone on the trip. There are 72 seats on each school bus. How many buses are needed for the field trip?
There are 109 fifth graders + 115 sixth graders + 118 seventh graders = <<109+115+118=342>>342 students going on the trip.
There are 4 teachers + 2 parents = <<4+2=6>>6 adults going on the field trip for each grade.
There are 3 grades going, so 3 grades x 6 adults/grade = <<3*6=18>>18 total adults going on the trip.
There are 342 students + 18 adults = <<342+18=360>>360 people going on the trip.
So, 360 people / 72 seats = <<360/72=5>>5 buses
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