TEACHER-GUIDE-VERIFIED · TG-V9-050

7. A detector count begins at 6,400 and halves every 3 hours. Find the count after 9 hours.

Verified solution

Solution: Nine hours is 3 half-life intervals. Count=6,400(1/2)^3=800.

Source: Teacher Guide V9 · English V9. Match the numbers and wording in your printed question before using this solution.

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VIDEO HELP · TG-V9-050

Count Three Half-Life Intervals (TG-V9-050)

A detector count starts at 6,400 and halves every three hours. Nine hours gives three intervals: 6,400(1/2)³ = 800. Check the counts at 0, 3, 6 and 9 hours.

Space Math Explorers · approved worked example · 1:12 · Watch on YouTube

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These pages reproduce verified solution steps for the registered V9 questions. It does not diagnose learning needs or replace instruction from a qualified teacher or tutor.