# Hard SAT Math Question 86 — Video Explanation | 1600.now

Source: https://1600.now/hard/86

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86

A scientist is using a sample of Technetium-99m with $23$-tera atoms. The number of Technetium-99 m's tera atoms decays in half every $6$ hours. Which of the following functions $T$ gives the number of tera-atoms $n$ days from now?

A

$T(n) = 23(2)^{4n}$

B

$T(n) = 23(3)^{n/4}$

C

$T(n) = 23(1/2)^{4n}$

D

$T(n) = 23(1/2)^{n/4}$