To find the cost per yard, divide the cost by the amount:
p: 6.25 / 6.5 = 0.96 --> The cost per yard is $0.96 r: 3 /4 = 0.75 --> The cost per yard is $0.75 b: 8.1 /8.5 = 0.95 --> The cost per yard is $0.95 s: 7.2 / 6 = 1.2 --> The cost per yard is $1.20
In order from cheapest to most expensive: Red Brown Purple Silver