Total weight of Rupesh, Mandar, and Ketan =45×3=135kg Total weight of Rupesh and Mandar =43×2=86kg Total weight of Mandar and Ketan =45×2=90kg Let Mandar's weight =M, Rupesh's weight =R, and Ketan's weight =K R+M+K=135 R+M=86 M+K=90 From R+M=86 ⇒R=86−M From M+K=90 : ⇒K=90−M Substitute R and K into R+M+K=135 : ⇒(86−M)+M+(90−M)=135 ⇒86+90−M=135 ⇒176−M=135 ⇒M=176−135 ⇒M=41