See picture for rough graph
I think the answer would be C. (btw, you should charge your phone/tablet, lol)
Where x is the length of the first piece

so the first piece is 3 inches, the second is 6 inches and the third is 19 inches
The answer is 180.add 40 to its self or multiply by 4 then add 20 for the .5 portion, 40x4=160 160+20=180.
hoped this helped =)