
Patrick B. answered 07/22/21
Math and computer tutor/teacher
He did C cards and M motorcycles
C + M = 100
4C + 2M = 310
But M = 100-c, so
4c + 2(100-c) = 310
4c + 200 - 2c = 310
2c + 200 = 310
2c = 110
c = 55
M = 100-c = 100-55 = 45
55 cars and 45 motorcycles have
55*4+45*2 = 220 + 90 = 310 tires
55 cars and 45 motorcycles