Question

A certain quantity decays exponentially over time. The initial quantity at t = 0 is 25,000. The quantity decays at a rate of 5%. What is the quantity at t = 3? A. 3.125 B. 21,434.375 C. 28,940.625 D. 3,125,000.000

Answer 1

For this case we have an equation of the form:
y = A * (b) ^ t
Where,
A: initial amount
b: decrease rate
t: time
Substituting values we have:
y = 25000 * (0.95) ^ 3
y = 21434.375
Answer:
the quantity at t = 3 is:
B. 21,434,375