Brother = 1 unit, Terence = 3 units. Terence is 48 kg heavier, so the gap of 2 units is 48 kg.

Brother1Terence11148 kg heavier = 2 units

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

  1. Terence − Brother = 2 units → 48 kg
  2. 1 unit → 48 ÷ 2 = 24 kg (brother)
  3. Total = 4 units → 4 × 24 = 96 kg

The total mass is 96 kg.

Check: Terence 72 + brother 24 = 96 kg, and 72 − 24 = 48 kg. ✓