The third-and fourth-grade teachers are planning a field trip. There are 173 third graders and 124 fourth graders. Each seat on the buses fits & students
Which expression represents the closest estimate of the number of seats on the buses that are needed for the students?
a. (175 − 125) × 3
b. (175 + 125) ÷ 3
c. (180 - 130) × 3
d. (180 + 130) ÷ 3