A bus holds 45 students. How many buses were taken on a field trip if 13 students travels by car and

A bus holds 45 students. How many buses were taken on a field trip if 13 students travels by car and total of 320 students went on a trip?

Find the number of students who went on the bus:
Number of students who went on the bus = Total students on field trip - students who traveled by car
Number of students who went on the bus = 320 - 13
Number of students who went on the bus = 307

Calculate the number of buses needed:
Number of buses needed = Number of students who went on the bus / Bus Capacity
Number of buses needed = 307 / 45
Number of buses needed = 6.822
We round up for a full bus to get 7 buses