Let the three girls Reshma, Salma and Mandip are standing on the circle of radius 5 cm at points R,S and M respectively.Here, chord RS= chord SM.∴center O lies on bisector of ∠RSM i.e. ray OSNow, RS=SM=6 m. Let OA⊥ chord RMRA=AM        ....perpendicular from center to the chord, bisects the chord.In △SAR, ∠A=90oSR2=SA2+RA2           ....Pyhtagoras theorem⇒36=SA2+RA2⇒RA2=36−SA2        ... (1)In the △OAR, RO2=AO2+RA2         ....Pythagoras theorem⇒25=(OS−AS)2+RA2⇒RA2=25−(OS−AS)2RA2=25−(5−AS)2           ... (2)From (1) and (2) , we get36−SA2=25−(5−SA)2⇒11−SA2+(5−SA)2=0⇒11−SA2+25−10SA+AS2=0⇒10SA=36⇒SA=3.6Putting SA=3.6 in (1) we getRA2=3.6−(3.6)2=36−12.96⇒36−12.96=23.04 m∴RA=4.8m ⇒RM=2RA=2×4.8=9.6 mHence, the distance between Reshma and Mandip =9.6 m