Question 19
The source asks: “$p$ and $q$ are prime numbers. Given $2p+5q=2019$, find $p-q$.” Its original options are A: 992, B: 984, C: 889, D: 968, E: None of the above. Analyse whether the stated conditions uniquely determine $p-q$, and justify your answer.
Source limitation: no restriction selecting a unique prime pair is printed, and the cover instructions supply none. Retain all original choices as source material; give a reasoned analysis rather than assuming that one choice must be uniquely implied.
Source limitation: no restriction selecting a unique prime pair is printed, and the cover instructions supply none. Retain all original choices as source material; give a reasoned analysis rather than assuming that one choice must be uniquely implied.