Question #dd0a0

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Answer 1 · 2017-02-25T03:53:40

#1/8#

You can logic it out, or use the equation.

logic method

A half life is the time it takes for there to be half the amount. The total time is 72000 and the half life is 24000,

then there have been #72000/24000 =# 3 half-lives in this time.

Thus, a half of a half of a half = #1/2 * 1/2 *1/2# = #1/8# the original amount.

equation method

#"Final Amount" = "Initial Amount" * (0.5)^("Time"/"Half Life")#

#"Final Amount" = "Initial Amount" * (0.5)^3#

#"Final Amount" = 1/8"Initial Amount"

And so the fraction is #1/8#