system of equations word problems

Question

A class of 195 students went on a field trip. They took 7 vehicles, some cars and some buses. Find then umber of cars and the number of buses they took if each car holds 5 students and each bus hold 45 students.

Answer 1

C + B = 7

5C + 45B = 195 divide by 5

C + 9B = 39 subtract 1st equation

C + B = 7

8B = 32

B = 4 buses

C=7-4 = 3 cars

5(3) + 45(4) = 15 + 180 = 195