Algebra and Trigonometry 10th Edition

When $t=75,000~years$: $Q\approx1.85~grams$
$Q=16(\frac{1}{2})^{\frac{t}{24,100}}$ When $t=75,000~years$: $Q=16(\frac{1}{2})^{\frac{75,000}{24,100}}=16(\frac{1}{2})^{3.112}\approx1.85$