Question

85 vehicles with a total of 188 wheels registered for a bike/trike race. How many vehicles and how many tricycles were at the race?

Answer 1

x = number of bicycles y = number of tricycles
x + y = 85 (1)
2x + 3y = 188 (2)

(1)*-2 = (3) -2x - 2y = -170 (3)
(2)+(3) = (4) y = 18 (4)

substitute y into 1st equation (1)
x + 18 = 85
x = 67

67 bikes, 18 tricycles