Norachai and Carlos each improved their yards by planting rose bushes and ornamental grass. They bought their supplies from the same store. Norachai spent $112.70 on 7 rose bushes and 4 bunches of ornamental grass. Carlos spent $240 on 12 rose bushes and 12 bunches of ornamental grass. Find the cost of one rose bush and the cost of one bunch of ornamental grass.