Percentage of a radioactive sample decayed in a given time from its half-life

The same question, asked 2 times: 15 May 2023 S1*, 19 Apr 2026 S1. Every wording below, oldest first.

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Question 1
15 May 2023 S1
24 $A radioactive substance has half-life of 60 minute. During 3 hour, the amount of substance decayed would be$
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Question 2
19 Apr 2026 S1
147 $5$
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