Use the Following to Answer Questions

Multiple Choice

Use the following to answer questions:
Suppose that of 300 mice in a mice colony born in January, 150 are still alive at the start of September, and 120 are still alive at the start of October.
-What is the mortality rate during the month of September?

A) 0.15
B) 0.20
C) 0.30
D) 0.50
E) 0.80