Concept:Use the LCM method to assign work units and compare daily work rates of P and Q.Explanation:Let total work be LCM(14,21)=42 units.P’s daily work =42÷14=3 units.Q’s daily work =42÷21=2 units.Since P leaves 3 days before completion, Q works alone for the last 3 days.Work done by Q alone in these 3 days =3×2=6 units.Remaining work done by P and Q together =42−6=36 units.Combined daily work of P and Q =3+2=5 units.Time taken together for remaining work =36÷5=751​ days.Total time =3+751​=1051​ days.
Answer:The work is completed in 1051​ days.This is not exactly listed among the given options, so the options appear to contain an error.