Question

A circular Petri dish has a diameter of 10 centimeters. If the dish contains 2,450 bacteria, what is the population density of bacteria in the fish?

(1) 31 bacteria per square centimeter
(2) 42 bacteria per square centimeter
(3) 48 bacteria per square centimeter
(4) 51 bacteria per square centimeter

Answer 1

Density=population/area circle, radius=10/2=5 cm
Density=population/(πr²)=2450/(π*5²)≈31
(1) 31 bacteria per square centimeter