Tony’s money never changes. Make the two ratios share Tony: 6:7 and (after) 1:2 = 7:14. Splitting each old unit into 2 small units, Tony = 14 small units, Shaw was 12 and becomes 7. The $500 spent is the 5-small-unit drop.

TonyShaw firstShaw afterspent $500 = 5 small units

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

  1. Match Tony in both ratios → 6:7 and 1:2 = 7:14 (small units: Shaw 12 → 7, Tony 14)
  2. Shaw’s drop → 12 − 7 = 5 small units → $500
  3. 1 small unit → $500 ÷ 5 = $100
  4. Shaw at first → 12 small units = 12 × $100 = $1200

Shaw had $1200 at first.

Check: Tony = 14 × $100 = $1400; after, Shaw $1200−$500=$700, and $700 : $1400 = 1 : 2. ✓