Time = Distance ÷ Speed Difference in time = Late time difference ⇒ Distance = Speed × Time Calculations: Let the correct time for the train to complete the journey be T hours. At S1, total time taken =T+1∕6 At S2, total time taken =T+1∕15 Distance covered at both speeds is the same: ⇒ Distance =S1×(T+1∕6)=S2×(T+1∕15) ⇒40×(T+1∕6)=45×(T+1∕15) ⇒40T+(40×1∕6)=45T+(45×1∕15) ⇒40T+40∕6=45T+45∕15 ⇒40T+20∕3=45T+3 ⇒20∕3−3=45T−40T ⇒20∕3−9∕3=5T ⇒11∕3=5T ⇒T=11∕(3×5) ⇒T=11∕15hr Convert T to minutes: ⇒T=(11∕15)×60 ⇒T=44min