Answer:
$220
Step-by-step explanation:
5/01: Beg. inventory: 10 × $10 = $100
5/03: Add inventory: 10 × $12 = $120
5/08: Less inventory: (10 × $12) + (2 × $10) = $140
5/15: Add inventory: 10 × $14 = $140
5/31: End. inventory: (10 × $14) + (8 × $10) = $220