1) A beam 9m long, 40 cm wide and 20 cm deepis made up of iron whihc weights 50 kg per cubic metre.FInd the weight of the beam? A) 30 kg B) 35 kg C) 36 kg D) 40 kg Answer: Option CExplanation:Volume of the beam=lbh =9×40100×20100=72100m3 The weight of the iron beam is given as 1m3=50kg ∴72100m3=72100m3 =72100×50=36kg