[
  "Convert 2400 g to kg: 2400 ÷ 1000 = 2.4 kg. Draw a bar model: Brian has 1 longer bar, Alan has 1 shorter bar (gap = 2.4 kg), total = 69.7 kg.",
  "To find Brian (the heavier one): (Total + Gap) ÷ 2.",
  "(69.7 + 2.4) ÷ 2 = 72.1 ÷ 2 = 36.05 kg for Brian."
]