The population of bacteria in thousands after hours is modelled by P(t)=120t-6t^ 2 ,…

MATHEMATICS · Single correct · AP · Calculus AB · Analytical Applications of Differentiation · Analytical Applications of Differentiation

Problem

The population of bacteria in thousands after

t

hours is modelled by

P(t)=120t-6t^{2},\qquad 0\le t\le 20.

During which time interval is the population decreasing? (a)

0<t<10\text{ h}

(b)

t\ge10\text{ h}

(c)

t>10\text{ h}

(d)

0\le t\le20\text{ h}