💡 Correct Answer:
start both together when 7 ends flip it when 10 ends 3 mins left in 7 flip for 3 more total 4
ℹ️ Explanation:
Start both. When 7-min ends (3 mins left in 10-min), flip the 7-min. When 10-min ends, the 7-min has 3 mins left. Flip the 7-min — it runs 3 more minutes. 7–3 = 4 minutes measured.