Question

Three red rods are 2cm longer than two blue rods. Three blue rods are 2cm longer than four red rods. How long is each rod?

Answer 1

3r = 2b + 2
b = (3/2)r - 1
"Three blue rods are 2 cm longer than four red rods"
3b = 4r + 2
3[(3/2)r - 1] = 4r + 2
(9/2)r - 3 = 4r + 2
(1/2)r = 5
r = 10 cm
b = (3/2)(10 cm) - 1
b = 14 cm