Children = 1 unit, adults = 4 units. Altogether 5 units = 860. Adults have 3 units more than children.

Children1Adults1111860

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

  1. 5 units → 860
  2. 1 unit → 860 ÷ 5 = 172 (children)
  3. Adults − Children = 3 units → 3 × 172 = 516

There are 516 more adults than children.

Check: children 172 + adults 688 = 860, and 688 − 172 = 516. ✓