Question

A colony of bacteria decreases in population by 10 percent each hour. The initial bacteria culture contained 250 spores. What exponential equation can be used to find the terms in the geometric sequence?(1 point)
Responses

b(x)=250(0.90)x−1

b left parenthesis x right parenthesis equals 250 left parenthesis 0.90 right parenthesis superscript x minus 1 baseline

b(x)=250−10(x−1)

b left parenthesis x right parenthesis equals 250 minus 10 left parenthesis x minus 1 right parenthesis

b(x)=250(0.99)x−1

b left parenthesis x right parenthesis equals 250 left parenthesis 0.99 right parenthesis superscript x minus 1 baseline

b(x)=250(0.10)x−1

Answer 1

b(x) = 250(0.90)^{x-1}

Reason: a geometric sequence uses a_n = a_1 r^{n-1}. A 10% decrease leaves 90% each hour, so r = 0.90 and a_1 = 250.