I have been given an assingment where I must show that the properties of the up, down and strange quarks follow from the properties of the baryons. I am just wondering why delta +1 (a baryon) has a spin 3/2 when it is, like a proton, composed of up, up, down. Aren't spins additive? and how do all of the 3/2 and 1/2 spin baryons follow from the combination of the up, down, and strange quarks alone? I can count only 10 combinations of those 3 types.