Big John is 3 equal units and Little John is 1 unit, so the difference is 2 units.

Little1Big111difference = 88 kg

Plain numbers are given; italic underlined numbers are worked out.

  1. Big − Little = 2 units → 88 kg
  2. 1 unit → 88 ÷ 2 = 44 kg
  3. Big John = 3 units → 3 × 44 = 132 kg

Big John’s mass is 132 kg.

Check: 132 − 44 = 88 kg, and 132 = 3 × 44. ✓