Your formula is right but you must have plugged it in wrong.
Y= 1/10 x
X is your distance, so plug in 85 with x
Y= 1/10 85
One- tenth as a decimal equals 0.1. So 0.1 times 85 will equal 8.5
I think answer is B.I am not sure because I found purple it is 1.350 but I found the yellow is 240 and it is more close to 420.I telling you I am not sure but this is my opininon.
