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Question 1
Suppose a radioactive substance decays at a rate of $4 \%$ per hour.
Question 2
How long does it take until the substance is half of its oriainal weight?
Answer
\(\boxed{16.98}\) hours for the substance to decay to half of its original weight.
Step 1 ：Suppose a radioactive substance decays at a rate of $4 \%$ per hour.
Step 2 ：How long does it take until the substance is half of its original weight?
Step 3 ：Use the formula for exponential decay: \(final\_amount = initial\_amount \times (1 - decay\_rate)^{time}\)
Step 4 ：Set up the equation: \(0.5 \times initial\_amount = initial\_amount \times (1 - 0.04)^{time}\)
Step 5 ：Solve for time: \(time \approx 16.98\)
Step 6 ：\(\boxed{16.98}\) hours for the substance to decay to half of its original weight.
