Cut the salary into 6 equal units (sixths). Wife takes 2⁄3 = 4 units, parents take 1⁄6 = 1 unit, leaving 1 unit.

wife 2/3parents 1/6left6 units = $1950

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

  1. 6 units → $1950
  2. 1 unit → $1950 ÷ 6 = $325
  3. Left → 1 unit = $325

He has $325 left.

Check: wife $1300 + parents $325 + left $325 = $1950. ✓