I think they mean at the bottom of p216 (pdf page 4), where he says he doesn't know, r+s=80 but there isn't enough information to solve for r and s.
I think they mean at the bottom of p216 (pdf page 4), where he says he doesn't know, r+s=80 but there isn't enough information to solve for r and s.
There's two questions that are intended to be wrong (probably to test confidence). One with insufficient information and where the question itself implies falsehoods.