An aeroplane files around a square field ABCD of each side 1000 𝑘𝑚. Its speed along 𝐴𝐵 is 250 𝑘𝑚 ℎ−1 , along 𝐷𝐴 100 𝑘𝑚 ℎ −1 . Its average speed (in 𝑘𝑚 ℎ −1 ) over the entire trip is a) 225.5 b) 175.5 c) 125.5 d) 190.5

Question :An aeroplane files around a square field ABCD of each side 1000 𝑘𝑚. Its speed along 𝐴𝐵 is 250 𝑘𝑚 ℎ−1 , along 𝐷𝐴 100 𝑘𝑚 ℎ −1 . Its average speed (in 𝑘𝑚 ℎ −1 ) over the entire trip is