Matthew and Susan are both optimising consumers in the markets for shirts and hats, where they pay $100 for a shirt and $50 for a hat. Matthew buys 4 shirts and 16 hats, while Susan buys 6 shirts and 12 hats. From this information, we can infer that Matthew’s marginal rate of substitution is hats per shirt, while Susan’s is .

a 2, 1 b 2, 2 c 4, 1 d 4, 2