Question

A laboratory culture contains 150 bacteria. After twenty minutes, the culture contains 300 bacteria. After one hour, the culture contains 1200 bacteria. Make a conjecture about the rate at which the bacteria grow.
a.The number of bacteria quadruples every 20 minutes.
b.The number of bacteria doubles every 20 minutes.
c.The number of bacteria doubles every 40 minutes.

Answer 1

b

Answer 2

Doubles in 20 minutes, doubles again after forty minutes to 600, doubles again at 60 minutes to 1200.

Answer 3

doubled twice is four times (in 40 minutes)