Can someone me with this problem? i don't understand.

Multiplying an even number of negative numbers gives an answer that is choose from:

According to the 2008 u.s. census, california had a population of approximately 4 × 10^7 people and florida had a population of approximately 2 × 10^7 people. which of the following is true? a. the population of florida was approximately two times the population of california. b. the population of florida was approximately twenty times the population of california. c. the population of california was approximately twenty times the population of florida. d. the population of california was approximately two times the population of florida.

Which expression is rational? 6. , square root two, square root 14, square root 49